What is Chemistry? 5 Branches of Chemistry

Summary

This script delves into the complex nature of chemistry, often perceived as a disorganized amalgamation of topics. Despite its seemingly chaotic structure, chemistry is revealed as the 'Central Science,' interlinking with various disciplines like biology, geology, and astronomy. The video emphasizes the historical roots of chemistry, from ancient alchemy to the scientific method, and underscores its foundational role in understanding the world at a molecular level. It also outlines the five main branches of chemistry and their significance, encouraging viewers to appreciate chemistry's broad applications and interconnectedness with other sciences.

Takeaways

• 🧪 Chemistry is often perceived as a disorganized subject, encompassing a vast array of topics from the composition of matter to various types of reactions and energy changes.
• 📚 Despite its complexity, chemistry is not a young science; it has roots dating back to ancient civilizations, with historical periods like the Iron and Bronze Ages named after metallurgical advancements.
• 🔮 Alchemy, with its mystical and philosophical underpinnings, represents an early form of chemistry, where practitioners sought to understand and transform matter, including the pursuit of the Philosopher's Stone.
• 🌐 Chemistry is foundational to many disciplines and is aptly called 'The Central Science', connecting fields like physics, biology, geology, and astronomy through the study of matter and its interactions.
• 🔬 The importance of chemistry is underscored in advanced studies of biology, where a lack of chemical knowledge can impede a deep understanding of biological processes and molecules.
• 🌌 In astronomy, chemistry is crucial for understanding the composition of stars and celestial bodies, with spectral lines being a key tool for identifying elements and molecules in space.
• 🌋 Geology, at its core, is intertwined with chemistry, as rocks and minerals are chemical in nature, and the study of their formation, erosion, and interaction with the environment is inherently chemical.
• ⚙️ Engineering, particularly in the development of new materials and energy solutions, relies heavily on chemical knowledge to innovate and solve complex problems.
• 🔬 The interdependence of physics and chemistry is highlighted, with a strong foundation in physics being beneficial for understanding chemical phenomena and vice versa.
• 📈 The branches of chemistry include Organic, Inorganic, Physical, Analytical, and Biochemistry, each with its own focus but with significant overlap and interconnectedness.

Q & A

Why did the speaker find chemistry disorganized during their studies?

The speaker found chemistry disorganized because it seemed like a collection of random, unrelated topics, unlike subjects like math or physics which have a more structured approach.

How does the lack of a textbook and multiple professors affect the speaker's perception of chemistry?

The lack of a textbook and the input from multiple professors, each emphasizing different aspects, contributed to the speaker's feeling of disorganization and lack of a clear structure in chemistry.

What is the historical evidence that suggests chemistry is not a young science?

Chemistry is not a young science because historical advancements in metallurgy, such as the Iron Age and Bronze Age, as well as the ancient Greeks' four elements theory and the practices of alchemists, indicate a long-standing study of chemical processes.

What was the role of alchemists in the early development of chemistry?

Alchemists played a significant role as early chemists, seeking to understand and manipulate matter, with goals such as creating the Philosopher’s Stone for eternal life and transmuting base metals into gold.

Why do we have limited knowledge about the earliest alchemy texts?

We have limited knowledge about the earliest alchemy texts because most were lost when the Great Library of Alexandria burned down in 391 AD.

How did the term 'chemistry' evolve linguistically from its ancient Egyptian roots?

The term 'chemistry' evolved from 'Khem' (black land), the name Greeks gave to Egypt, to 'al-Khemia' by the Arabs, and eventually to 'alchemy' and modern 'chemistry' as the practice spread to the West.

What is the significance of the 'Philosopher’s Stone' in alchemy?

The 'Philosopher’s Stone' was significant in alchemy as it was believed to grant eternal life and the ability to transmute base metals into gold, symbolizing the perfection of matter.

Why did the speaker refuse to accept students without a chemistry background in their advanced biology class?

The speaker refused to accept students without a chemistry background because a significant portion of the class content was chemistry-related, particularly biochemistry, which is essential for understanding biological processes.

How does chemistry earn the title 'The Central Science'?

Chemistry is called 'The Central Science' because it connects to many other disciplines, providing foundational knowledge necessary for a deeper understanding of fields like biology, geology, and astronomy.

What are the five main branches of chemistry mentioned in the script?

The five main branches of chemistry mentioned are Organic Chemistry, Inorganic Chemistry, Physical Chemistry, Analytical Chemistry, and Biochemistry.

Why is it recommended to study physics before chemistry according to the speaker's suggested science study plan?

The speaker recommends studying physics before chemistry to establish a basic understanding of concepts that help explain chemical phenomena, as chemistry relies heavily on physical laws and principles.

Outlines

00:00

🧪 The Complexity and History of Chemistry

The speaker begins by expressing their initial confusion with chemistry, feeling it lacked the structured progression of other sciences. They describe chemistry as a vast field that encompasses a wide range of topics, from the composition of matter to various types of reactions and energy changes. The speaker reflects on their college experience at Caltech, where the absence of a textbook and a structured curriculum further contributed to this feeling. Despite this, they acknowledge that chemistry is not a new science; it has deep historical roots, with early forms of chemistry evident in the practices of ancient civilizations. The discussion touches on the contributions of alchemists, who, despite being more mystical than scientific, laid some of the foundational observations that would later become systematic chemistry. The speaker also highlights the loss of early alchemy texts due to historical events like the burning of the Great Library of Alexandria but notes that some writings have survived, offering insights into the pre-scientific exploration of chemistry.

05:02

🔬 Chemistry as the Central Science

The speaker emphasizes the central role of chemistry in various scientific disciplines, likening it to a hub that connects to physics, biology, geology, and more. They argue that a strong foundation in chemistry is essential for a deeper understanding of these fields. The speaker discusses the importance of chemistry in biology, explaining how biological processes are fundamentally chemical reactions. They recount a personal anecdote about advocating for chemistry prerequisites in advanced biology classes, highlighting the interdependence of these subjects. The paragraph concludes with a call to action for viewers to sign up for the Chemistry Club mailing list to stay informed about educational resources provided by Socratica, including videos, quizzes, and practice tests.

10:08

🌌 Chemistry's Relevance in Astronomy, Geology, and Engineering

The speaker explores the relevance of chemistry in fields beyond biology, starting with astronomy. They explain how chemistry is crucial for understanding the composition of stars and celestial bodies, as well as the generation of elements within them. The discussion moves to geology, where chemistry is fundamental to understanding the properties and transformations of rocks and minerals. The speaker also touches on engineering, particularly in the development of new materials and energy solutions. They stress the interdependence of physics and chemistry, suggesting a learning path that starts with basic physics, moves to chemistry, and then to other sciences, with a recommendation to circle back to physics for a deeper understanding.

15:09

📚 Branches of Chemistry and Their Applications

The speaker outlines the five main branches of chemistry: Organic, Inorganic, Physical, Analytical, and Biochemistry. They describe Organic Chemistry as the study of carbon-based compounds, crucial for understanding life. Inorganic Chemistry is presented as the study of non-living chemical compounds, with applications in various industries. Physical Chemistry is the application of physics to explain chemical phenomena, while Analytical Chemistry involves the measurement and analysis of chemical properties using various lab equipment. Biochemistry, the study of the molecules of life, relies on techniques from other branches of chemistry. The speaker notes the arbitrary nature of these divisions and mentions the existence of many specialized fields within chemistry, emphasizing the vastness and interconnectedness of the discipline.

Keywords

💡Chemistry

Chemistry is the scientific study of the composition, structure, properties, and reactions of matter. In the video, it is described as a vast and diverse field that encompasses the study of everything related to how matter behaves. It is portrayed as a 'grab-bag of random, unrelated topics' and is contrasted with other sciences like Math or Physics, which are seen as more neatly organized. The video discusses how chemistry is foundational to understanding the world around us, from the composition of elements to the reactions that drive life processes.

💡Alchemy

Alchemy is an ancient philosophical and protoscientific tradition that aimed to transform base metals into noble ones, especially gold, and to find a means of creating an elixir of life. In the video, alchemy is presented as a precursor to modern chemistry, with alchemists being seen as 'pre-scientists' who sought to understand and manipulate matter in pursuit of transmutation and the creation of the Philosopher’s Stone.

💡Transmutation

Transmutation refers to the process of converting one element or substance into another. In the context of the video, it is mentioned as a central goal of alchemists who believed that substances could evolve or develop towards a more perfect state. This concept laid the groundwork for the understanding of chemical reactions and the transformation of matter, which is a core aspect of chemistry.

💡Philosopher’s Stone

The Philosopher’s Stone is a legendary alchemical substance said to turn base metals into gold and grant eternal life. In the video, it symbolizes the alchemists' pursuit of knowledge and power over nature. It is used to illustrate the historical context and the early motivations behind the study of chemistry.

💡Physical Properties

Physical properties are characteristics of a substance that can be observed without changing the identity of the substance, such as color, state (solid, liquid, gas), density, and melting point. The video mentions physical properties as one of the many topics within chemistry, highlighting the broad scope of the subject.

💡Chemical Properties

Chemical properties are characteristics that become evident during or after a chemical reaction, such as reactivity, flammability, and oxidizing ability. The video includes chemical properties as part of the wide array of topics that chemistry covers, emphasizing the study of how substances interact and change.

💡Types of Reactions

Types of reactions refer to the various ways in which chemical reactions can occur, such as synthesis, decomposition, single displacement, double displacement, and combustion. The video touches on this concept to illustrate the complexity and diversity within the field of chemistry, where understanding different reaction types is crucial.

💡Energy

Energy in the context of chemistry refers to the capacity of a system to perform work. It is a central theme in the video, as it is involved in many chemical processes, such as reactions that release or absorb energy. The video discusses how chemistry is not only about the study of matter but also the energy changes that accompany chemical transformations.

💡Central Science

The term 'Central Science' is used in the video to describe chemistry's role as a connecting discipline that bridges various scientific fields. It is positioned as a hub that links to physics, biology, geology, and more, emphasizing the importance of a chemical understanding for advancing knowledge in these related areas.

💡Biochemistry

Biochemistry is the study of chemical processes within and relating to living organisms. In the video, it is highlighted as a branch of chemistry that is integral to understanding biology, as it deals with the molecular mechanisms, reactions, and interactions that occur in living systems.

💡Molecular Biology

Molecular biology is the field of biology that focuses on the molecular basis of biological activity, including the structure, function, and interactions among the molecules of cells. The video mentions molecular biology to underscore the interdependence between chemistry and biology, especially in understanding the chemical nature of biological processes and molecules.

Highlights

Chemistry is perceived as a disorganized subject with a vast range of topics.

Chemistry textbooks cover a broad spectrum of topics without a clear linear progression.

The lack of a textbook in the speaker's freshman chemistry class at Caltech contributed to a disjointed learning experience.

Chemistry is an ancient science, with historical roots dating back to the Iron and Bronze Ages.

Alchemy, with its mystical and philosophical underpinnings, laid the groundwork for early chemistry.

The term 'chemistry' originates from the Arabic 'al-Khemia', reflecting the historical significance of Egypt in the field.

Alchemy aimed to transmute base metals into gold and sought the Philosopher's Stone for eternal life.

Early chemists, or alchemists, were more like pre-scientists, blending mysticism with empirical observations.

The scientific method began to supersede alchemy in the 18th and 19th centuries, marking the start of modern chemistry.

Chemistry is often referred to as 'The Central Science' due to its interdisciplinary connections.

A strong foundation in chemistry is essential for understanding advanced concepts in biology, astronomy, and other sciences.

The speaker emphasizes the importance of prerequisite chemistry knowledge for students entering advanced biology classes.

Chemistry is integral to understanding biological processes such as cell reproduction and metabolism.

Astronomy's modern practices are deeply intertwined with chemistry, especially in the study of stellar composition and spectral lines.

Geology is fundamentally a chemical science, with rocks and minerals being the subject of chemical analysis.

Chemistry plays a crucial role in engineering, particularly in material science and energy solutions.

Physics and chemistry are interdependent, with each providing foundational concepts for the other.

The speaker suggests a study order starting with physics, followed by chemistry, biology, and then more specialized fields.

There are five commonly recognized branches of chemistry: Organic, Inorganic, Physical, Analytical, and Biochemistry.

Each branch of chemistry has distinct focuses and applications, from understanding life's molecules to analyzing chemical properties.

Chemistry's interdisciplinary nature is highlighted by its overlap with other specialized fields like Forensic and Environmental Chemistry.

Transcripts

Chemistry made me CRAZY as a student—because it seemed like a thrown-together subject.

Just a grab-bag of random, unrelated topics.

Even after teaching chemistry for many years, in some ways, I still feel that way.

If you page through a chemistry textbook, it jumps around from the composition of compounds,

elements,atoms, ions, physical properties, chemical properties, types of reactions, energy

changes...It seems like in Chemistry, we study just everything anyone has ever figured out

about how matter behaves.

It’s not nicely organized like Math or Physics or Biology.

I never got the sense of you start with this fundamental thing, and then this follows,

and that leads to this..

This feeling was exacerbated by my freshman-year chemistry class in college, at Caltech.

We didn’t have a textbook.

We had several professors that year, just come in and talk about what THEY thought was

important in Chemistry.

Don’t get me wrong—I learned a lot, but it didn’t help me develop a sense of how

the subject was organized or could be organized.

I had no idea what subject could be coming next, no idea how the topics could be connected

to each other.

Because the subject is so disorganized—You would THINK that means Chemistry is a young

science, but no - that’s not true.

That’s not the reason.

People have been studying chemistry ever since cavemen mixed together pigments to do their

cave paintings.

The “Iron Age,” the “Bronze Age” - we actually named entire historical time periods

after advances in metallurgy.

How long ago do you think gunpowder was invented?

The ALCHEMISTS are probably the closest to what we would recognize as early chemists.

There were the ancient Greeks with their four elements of nature: Earth, Fire, Air, and

Water - and they combined their philosophy with the Egyptians and their mystical rituals

about rebirth, associated with the Nile river and its rich black soil they called Khem.

The Greeks called Egypt KHEMIA.

Then in the 7th century, Egypt was occupied by the Arabs, and they added “al-” to

form the word “al-Khemia” - the black land.

Alchemy was introduced to the West in the 8th century, when the Arabs brought it to

Spain, and eventually it spread as far as India and China.

Sadly, we’ve lost most of the earliest alchemy texts because in the year 391 the Great Library

at Alexandria burned.

But we do have some very interesting writings about alchemy from the Middle Ages.

Those Alchemists got kind of a bad rap as a bunch of kooks.

I don’t think we should sneer at their efforts because they weren’t scientists, exactly.

They were sort of like PRE-scientists.

Alchemists wanted to harness the power of nature and create the legendary Philosopher’s

Stone that would grant them eternal life.

They also wanted to use the Philosopher’s Stone to generate gold and other precious

materials out of less valuable “base matter” like lead.

They were pursuing Transmutation - they thought that substances could evolve, or develop towards

a more perfect state.

That’s the result of observing physical and chemical changes - and that’s where

you start to do chemistry.

The alchemists were doing their best to catalog their observations about how different kinds

of matter interacted, and that’s a scientific impulse—they just weren’t very systematic

about it, and they had a warped sense of logic because mysticism was intertwined in everything

they did.

If the alchemists observed something they didn’t understand, they made up a rule to

explain it - and these rules seem superstitious to us now.

They almost gave personalities to the different metals they worked with, and they thought

that a celestial object, as well as a day of the week, and an organ in the human body

- was connected to each element.

So for instance, Lead was connected to Saturn, and Saturday, and in your body, the Spleen.

Eventually, the work of early scientists or “natural philosophers” (that’s what

they were called in the 17th / 18th centuries) accumulated enough reproducible information

that scholars concluded the aims of alchemy were just not reasonable.

So maybe we should say Chemistry, as we know it, based on experimental evidence, started

around the 18th/19th century.

So can we start there, and describe what Chemistry IS?

Maybe in terms of other subjects we DO have a better handle on.

Before I go on, I want to encourage you to sign up for our Chemistry Club mailing list.

Here at Socratica, we’re building a series of chemistry videos to help you learn more.

For each video, there’s a free short quiz.

And if you want longer practice tests those are available for purchase on socratica.com.

When you sign up for our tastefully infrequent emails, you’ll get notified when there are

new releases.

Now back to unraveling this hairy problem of What IS chemistry.

Chemistry is often called “The Central Science” because it CONNECTS to many other disciplines.

You can picture it sitting in the middle like a giant hub of science knowledge.

You have physics over here, and physical chemistry.

Biology has biochemistry.

Here’s geology, and geochemistry.

Astronomy/ astrochemistry.

If you want to study these disciplines: biology, geology, astronomy, materials science...the

truth is, you won’t get very far into the nitty gritty unless you know some chemistry.

Of course you can learn some basics.

But you’re fooling yourself if you think you’ll have access to the whole field.

Chemistry is what gives you a more complete understanding, and it’s through a chemical

understanding that you’ll be able to talk with REAL biologists, REAL astronomers - and

not just a textbook written for beginners.

Back when I was teaching, I got in this huge argument with a micromanaging administrator

who tried to tell me it made no difference whether a student had the prerequisite of

chemistry before they took my advanced biology class.

I flatly refused to accept any students into my class who hadn’t studied any chemistry

because, guess what?

At least a third of my class WAS chemistry.

Biochemistry is about the subset of chemicals found in living organisms.

Molecular Biology is about MOLECULES.

How can you teach any real significant biology to someone who doesn’t know what molecules

are and how they behave, chemically?

It would be like saying you can take calculus before you take algebra.

I’m still mad.

I won, obviously, but I’m still mad that someone could be that dismissive of how important

chemistry is.

You see, in many ways, the study of biology is an EXTENSION of the study of chemistry.

All of life - every bit of our bodies - is made up of chemical compounds.

This is true of all living things.

Those chemicals interact with each other, sticking together to make larger compounds

or breaking apart to make smaller modules that can be reused, or exchanged for energy.

All the essential biological processes - cell reproduction, glycolysis, cellular respiration,

photosynthesis - these are all built up from a set of chemical reactions and exchanges

of chemical energy.

If you don’t understand the chemistry of biological molecules in plants and animals,

you won’t understand how these organisms reproduce, develop, grow, you won’t understand

diet or nutrition or hormone signalling, how we taste and smell, and see, or how animals

are able to move by contracting their muscles, or how the neurons in your brain function…

So, even if you consider yourself a biologist, or you want to major in biology, or medicine

for that matter, you’re not going to get very far unless you get a strong background

in chemistry.

I personally am a MOLECULAR biologist and so this was a big leveling up step for me

- to respect what I had to learn from chemistry before I could move forward in my chosen field.

Now let’s talk a little bit about how chemistry is relevant in other subjects you might be

interested in.

When kids are first interested in astronomy, we give them a telescope, which is a lot of

fun, but most modern astronomy isn’t about looking through a telescope with your naked

eye.

There’s a fundamental connection between chemistry and astronomy, and it includes how

elements are generated in fiery stars, or on the other side of the story, how molecular

clouds could give rise to stars.

You’ll hear a lot about “spectral lines” in astronomy - every element and molecule

emits light at specific frequencies, so we can use chemical spectrographs to identify

the composition of stars and other celestial objects.

Geology is another field that is basically chemistry at its heart.

Rocks and minerals ARE chemicals.

So you see geologists using a lot of the tools of chemistry in their work.

They have to examine the chemical composition of samples in order to understand hardness

and erosion.

There are gradual chemical changes as rocks and minerals interact with the environment

and break down over time.

The study of radioactive elements is essential for dating, like carbon dating.

Engineering is probably the most blue-sky area for extensions of chemistry.

Engineering is all about using science and math to solve problems, and we NEVER run out

of problems.

A big area of research right now is ENERGY - can we conserve energy or produce more energy?

Can we do a better job capturing solar energy and can we make more efficient batteries for

storing energy?

Chemists will help solve those problems.

A lot of engineering depends on how well you understand the materials you have to work

with.

What kind of stress can they withstand.

Are they going to break down when they come in contact with a cleaning solution?

Is it safe - chemically inert?

or is it volatile?

Chemistry is what lets you understand a material’s strength, appearance, whether it’s combustible,

and so on.

And, if you’re not satisfied with the materials that are out there, you can make new ones

by using applied chemistry, or chemical engineering.

Now Physics is a really interesting case.

Physics and chemistry are SO interdependent.

When I study chemistry, I find myself falling back on a lot of physics concepts to understand

why the chemistry works.

Why are particles moving this way, what’s the force of attraction or repulsion, why

is this form more stable...So even though we call chemistry the “Central Science,”

I might argue that it all really starts with physics.

You don’t need to study ALL of physics to understand chemistry, but it’s a good idea

to get familiar with the basic concepts, and then circle back later.

Similarly, you don’t need to study ALL of chemistry to understand physics.

But maybe start with atomic structure and in particular the behavior of electrons.

Here’s how I would actually suggest people study the sciences:

Physics first - on one level.

Basic, conceptual physics that doesn’t take much math.

Then Chemistry.

Then Biology.

Then, circle back to Physics and learn more, including the calculus.

Then branch out into Astronomy, Engineering, Materials Science - whatever tickles your

brain.

But set yourself up for success by understanding how interrelated all of these disciplines

are.

Chemistry will help you get there.

I think it wasn’t until I TAUGHT chemistry that I finally got a handle on what we know

in the subject, and what we’re still trying to figure out.

Even as an instructor, it’s challenging to know what to include in a given class,

and what to leave out.

If you look at different college catalogs, you’ll see the chemistry subjects broken

up in different ways.

If you ask a chemist “How many Branches of Chemistry are there?”

Some say 5, some say 6…I saw one list that said 10 - It depends on how you count them.

The most common answer I hear is 5 branches of chemistry: Organic Chemistry, Inorganic

Chemistry, Physical Chemistry, Analytical Chemistry, and Biochemistry.

Organic Chemistry is the study of chemical compounds that contain carbon.

This is really important for understanding life on Earth, because all living things have

carbon as the backbone of their molecules.

So organic chemists study the structure and properties of all these carbon-based molecules

- and there’s all kinds of applications in biotechnology, petroleum, plastics...

Inorganic Chemistry studies the rest of the chemical compounds.

Everything that’s inorganic, or nonliving.

That doesn’t mean these kinds of chemists NEVER study anything containing carbon - there’s

some crossover.

Industry applications include things like making fertilizer, creating chemical sunscreens,

studying pigments for paint…

Physical Chemistry is when you use Physics to explain chemical phenomena.

So, think about how we have physics equations to describe how objects move, forces of attraction,

wave behavior.

New physics emerges when you try to extrapolate to describe the physical behavior of tiny

things like atoms and molecules.

And of course, what the physical chemists discover gets incorporated into all the other

branches of chemistry, because everyone has to obey the laws of physics.

Analytical Chemistry is maybe the most quantitative of the chemical disciplines.

Take any chemical property, and figure out how to measure it and track it, and compare

it.

If you like fiddling with lab equipment - like mass spectrometers and bomb calorimeters and

chromatographs, and titrating!

- then maybe analytical chemistry is for you.

Biochemistry is the study of the molecules of life, and it relies on the same techniques

that other chemists use along with some specialized ways of studying things, for instance, the

exact 3-dimensional shape of proteins when they’re properly folded up, and the dynamics

of how they interact with each other, and how enzymes catalyze reactions, things like

that.

By the way - I made another video “What is Biochemistry” if you want to learn more

about what that field covers.

Keep in mind - this separation of 5 disciplines in chemistry is so arbitrary.

You can already see, there’s a lot of overlap between these 5.

And then there are a million specialized fields.

You can add Theoretical Chemistry, Forensic Chemistry, Environmental Chemistry, Nuclear

Chemistry...

I’m glad you’ve found Socratica, where you will Learn More.

That’s our promise to you.

You can do your part by signing up for our Chemistry Club mailing list, so you’ll learn

about new releases and other goodies we’re making for you.

Remember, for each video in our series, there’s a short quiz.

I’ve also created some longer practice tests so you can check yourself to see how much

have you actually learned.

A lot, I’m sure, you’ve learned a lot.

You can find those practice tests on socratica.com.

Thanks for watching.