Modern Periodic Table

Summary

This educational video script guides viewers through the creation of a 'mini' periodic table, focusing on elements up to calcium (atomic number 20). It explains the significance of atomic numbers over atomic mass, the arrangement of elements into periods and groups, and the electronic configurations that dictate an element's chemical properties. The script also touches on the history of the periodic table, the difference between the modern and Mendeleev's table, and the special cases of isotopes and elements like hydrogen. It concludes with a call to action for viewers to practice drawing the table and learn the first 20 elements, promising a future video on periodic trends.

Takeaways

• 🔬 The modern periodic table is based on atomic number rather than atomic mass, which corrects anomalies in Mendeleev's table.
• 📚 Elements are arranged in the periodic table by increasing atomic number, which determines their chemical properties.
• 📈 The number of electron shells in an element corresponds to its period number in the periodic table.
• 🔋 Elements in the same group of the periodic table have the same number of valence electrons, leading to similar chemical properties.
• 🌐 The periodic table is divided into periods (rows) and groups (columns), with each period representing an electron shell and each group representing elements with similar properties.
• 💡 The arrangement of elements in the periodic table allows for the prediction of an element's properties based on its position.
• 🌈 The periodic table is color-coded to distinguish between different types of elements, such as metals, non-metals, metalloids, and noble gases.
• 📊 The modern periodic table includes the lanthanide and actinide series, which are placed separately to maintain the table's compactness.
• 🧩 Elements in Group 1 are called alkali metals, and those in Group 2 are called alkaline earth metals, reflecting their chemical properties when reacting with water.
• 📖 The video script encourages viewers to practice drawing the periodic table and learning the first 20 elements to better understand and master the subject.

Q & A

What is the modern periodic table based on?

The modern periodic table is based on atomic number rather than atomic mass, which was the basis for Mendeleev's periodic table.

Why is atomic number a more fundamental property for elements than atomic mass?

Atomic number is a more fundamental property because it determines the chemical properties of elements more directly than atomic mass. Moseley's work proved this by showing that chemical properties are more closely related to atomic number.

What is the significance of the period number in the periodic table?

The period number indicates the number of electron shells or electron orbits present in an atom, allowing us to predict the number of shells without drawing the electronic structure.

How does the arrangement of elements in the periodic table reflect their chemical properties?

Elements with similar chemical properties are grouped together in the periodic table. This is because their chemical properties depend on the number of valence electrons, which is the same for elements within the same group.

What is the difference between the old and new group numbering schemes in the periodic table?

The new scheme numbers groups from 1 to 18, while the old scheme uses Roman numerals and letters (a and b) to designate groups. For example, Group 1 is '1' in the new scheme and 'I A' in the old scheme.

Why are isotopes able to fit into the modern periodic table but not Mendeleev's?

Isotopes fit into the modern periodic table because they have the same atomic number, which is the basis for the modern table's organization. Mendeleev's table, based on atomic mass, could not accommodate isotopes as neatly.

How does the modern periodic table address the anomalies present in Mendeleev's table?

The modern periodic table corrects anomalies by basing its organization on atomic number, which is a periodic function of the properties of elements. This corrects issues like the placement of isotopes and elements like cobalt and nickel.

What are the lanthanide and actinide series, and why are they placed separately in the periodic table?

The lanthanide series (elements 57-71) and actinide series (elements 89-103) are placed separately below the periodic table to compact it. These are rare earth elements and radioactive elements, respectively.

Why is hydrogen sometimes given special treatment in the periodic table?

Hydrogen is sometimes given special treatment because it shows properties similar to both Group 1 (alkali metals) and Group 17 (halogens), even though it is placed in Group 1.

What is the significance of the electronic configuration in determining the group an element belongs to?

The electronic configuration, specifically the number of valence electrons, determines the group an element belongs to. Elements in the same group have the same number of valence electrons, which results in similar chemical properties and valency.

Outlines

00:00

🔬 Introduction to the Modern Periodic Table

The script begins with an introduction to the modern periodic table, following discussions on earlier attempts to classify elements such as the double renews, triads, Newlands' law of octaves, and Mendeleev's sporadic table. The focus is on the modern periodic table, starting with a blank table and filling it up as the video progresses. The aim is to make viewers proficient in understanding the periodic table. The video will conclude with top three questions on the topic. The periodic table's shape is noted to be unusual, and the video will explain why. The table is filled up to the 20th element, calcium, covering only the first four rows, referred to as a 'mini periodic table.' Viewers are encouraged to sketch this mini table or take a printout for reference. The presenter then shrinks the table for better visibility and begins filling it up, starting with numbering the rows (periods) and columns (groups), explaining that rows are called periods and columns are called groups.

05:02

📊 Understanding Atomic Numbers and Periods

This section delves into the concept of atomic numbers, which are the number of protons in an element's nucleus. It contrasts the modern periodic table, based on atomic numbers, with Mendeleev's table, which was based on atomic mass. The importance of atomic numbers is highlighted due to Moseley's proof that they are more fundamental properties than atomic mass. The script then instructs viewers to fill in elements by atomic number, starting with hydrogen (H) for atomic number one, and continuing up to calcium, which has an atomic number of 20. It explains that as atomic numbers increase by one, so do the number of electrons, maintaining the atom's neutrality. The significance of periods (rows) is then discussed, indicating the number of electron shells or orbits in an atom. Examples are given for hydrogen, oxygen, and aluminum to illustrate how the period number correlates with the number of electron shells.

10:04

🌐 Grouping Elements by Similar Properties

The script explains the concept of grouping in the periodic table, where elements with similar chemical properties are placed together. It uses the analogy of a grocery store to illustrate the idea of grouping similar items for ease of use. The video then focuses on group 1 (alkali metals) and group 2 (alkaline earth metals), noting their similar valencies and chemical properties. The reason behind this similarity is explored through electronic configurations, showing that elements within the same group have the same number of valence electrons. The script also touches on the old group numbering scheme using Roman numerals and letters, providing a trick to remember the mapping between the old and new schemes by focusing on elements included in typical syllabuses.

15:06

🎨 Coloring the Periodic Table and Discussing Its Merits

This part of the script introduces the concept of coloring the periodic table to represent different types of elements, such as metals, non-metals, metalloids, and noble gases. It then discusses special names for certain groups, like alkali metals, alkaline earth metals, and noble gases. The script also briefly mentions the full periodic table, which includes seven periods and eighteen groups, and notes the placement of lanthanide and actinide series separately below the table to compact it. The merits of the modern periodic table are highlighted, particularly how it corrects anomalies in Mendeleev's table by being based on atomic number rather than atomic mass. The script concludes by encouraging viewers to practice drawing the mini periodic table and learn the first 20 elements, promising a separate video on trends in the periodic table and reminding viewers to subscribe and engage with the presenter's social media and website.

Keywords

💡Periodic Table

The Periodic Table is a tabular arrangement of chemical elements organized on the basis of their atomic number, electron configurations, and recurring chemical properties. In the video, the Periodic Table is the central theme, with the presenter guiding viewers through its structure and significance. The video discusses the evolution from early attempts to the modern periodic table, emphasizing the shift from atomic mass to atomic number as the organizing principle.

💡Atomic Number

Atomic Number refers to the number of protons found in the nucleus of an atom, which is unique to each element. The video explains that the modern periodic table is organized based on atomic number rather than atomic mass, highlighting the importance of atomic number in determining an element's position and properties. This is exemplified by filling in elements in the table according to their increasing atomic numbers.

💡Electron Configuration

Electron Configuration is the distribution of electrons in an atom's orbitals. The video uses electron configuration to explain the periodicity of elements, showing how the number of electron shells corresponds to the period number in the periodic table. For instance, hydrogen with one electron is in the first period, while oxygen with eight electrons is in the second period.

💡Alkali Metals

Alkali Metals are a group of metals belonging to Group 1 of the periodic table. They are characterized by having one electron in their outermost shell, giving them a valency of 1 and similar chemical properties. The video mentions that despite hydrogen's placement in Group 1, it is sometimes given special treatment due to its unique properties.

💡Alkaline Earth Metals

Alkaline Earth Metals, found in Group 2 of the periodic table, are another type of metal discussed in the video. Like alkali metals, they have two electrons in their outermost shell, resulting in a valency of 2. The video explains how their electronic configuration leads to similar chemical behaviors among elements within this group.

💡Valency

Valency, also known as valence, is the combining power of an element, determined by the number of electrons in the outer shell. The video emphasizes that elements in the same group of the periodic table have the same valency due to having the same number of valence electrons, which is why they exhibit similar chemical properties.

💡Isotopes

Isotopes are variants of a particular chemical element that have the same number of protons but different numbers of neutrons. The video clarifies that isotopes, which could not be accommodated in Mendeleev's periodic table based on atomic mass, fit neatly into the modern periodic table because they share the same atomic number and thus the same chemical properties.

💡Lanthanide Series

The Lanthanide Series refers to the group of elements with atomic numbers 57 to 71, which are placed separately below the main body of the periodic table to save space. The video mentions that these elements, starting with Lanthanum, are rare earth elements and are part of the modern periodic table's structure.

💡Actinide Series

Actinide Series includes elements with atomic numbers from 89 to 103, also placed below the main table. Starting with Actinium, these elements are radioactive, as explained in the video, and their separate placement helps to maintain the table's compactness and organization.

💡Mendeleev's Periodic Table

Mendeleev's Periodic Table is an earlier version of the periodic table organized by Dmitri Mendeleev based on atomic mass. The video discusses how the modern periodic table corrects anomalies present in Mendeleev's table by using atomic number as the basis for organization, thus better reflecting the periodic law.

Highlights

Introduction to the modern periodic table as the culmination of a journey through earlier attempts at classifying elements.

Explanation of the shift from Mendeleev's table based on atomic mass to the modern table based on atomic number.

Emphasis on atomic number as a fundamental property that determines the chemical properties of elements more than atomic mass.

Guidance on how to fill in the periodic table starting with a blank table and progressing to a complete 'mini' table up to calcium (element 20).

Discussion on the significance of period numbers in the periodic table, which represent the number of electron shells in an atom.

Illustration of how the number of electron shells corresponds to the period number using examples like hydrogen, oxygen, and aluminium.

Introduction to the concept of groups in the periodic table and their relation to elements with similar chemical properties.

Explanation of how the electronic configuration of elements within the same group leads to similar valency and chemical properties.

Overview of the old and new group numbering schemes in the periodic table and their significance.

Tutorial on how to remember the mapping between the old and new group numbering schemes using the syllabus as a guide.

Introduction to the color-coding system in the periodic table, which helps to visually distinguish between different types of elements.

Explanation of special group names such as alkali metals, alkaline earth metals, and noble gases, and their significance.

Discussion on the merits of the modern periodic table, including its ability to correct anomalies present in Mendeleev's table.

Example of how isotopes fit into the modern periodic table due to their identical atomic numbers.

Correction of the positions of elements like cobalt and nickel in the modern periodic table based on atomic number rather than atomic mass.

Special treatment of hydrogen in the periodic table due to its unique properties that align with both Group 1 and Group 17 elements.

Encouragement for viewers to practice drawing the periodic table and learning the first 20 elements for better mastery.

Invitation to subscribe to the YouTube channel, follow social media, and visit the website for more educational content.

Transcripts

hi friends in this video we look at the

last stop in our journey the modern

periodic table remember in the previous

videos we discussed the earlier attempts

to classify elements that is the double

renews triads Newlands law of octaves

and Mendeleev spiri otic table here we

are going to look at the modern periodic

table but we are going to do it in a

different and interesting way so rather

than starting with the periodic table we

are going to start with a blank table

and will fill it up as we go along in

this video I'm sure by the end of the

video you'll be a master of the periodic

table and as usual we'll finish off with

our top three questions on this topic

normally when you draw a table it looks

something like this with rows and

columns but if you take a look at our

periodic table it has a strange shape

and we are going to see why as I said

we'll start with a blank table and we

are going to fill it up as we go along

in this video since our focus is only

till the 20th element which is calcium

so we'll be looking only at the first

four rows of the periodic table let's

call this our mini periodic table we

will talk about the lower rows later on

in this video so I'd like you to pause

the video here and go ahead and sketch

our mini periodic table in your notebook

just draw this blank table till the

fourth row you can also pause the video

here and do a print screen and take out

a printout of the blank table friends

are you ready with your blank periodic

table I'm going to magically shrink

myself so that you can see this table

better and let's fill up this table

together first let's start by numbering

the rows so it's going to be 1 2 3 and

so on in our mini periodic table we have

only 4 rows but the full table has seven

rows rows are called P

so these are period numbers similarly we

can number the columns so the column

number is going to be one two three and

all the way up to 18 columns are called

groups in the periodic table so these

are our group numbers there is a

different numbering scheme for groups as

well but we'll look at that later on in

the video

next start numbering the boxes so start

from one to finish the first row then go

on to the second row 3 4 5 and so on

these numbers look like serial numbers

or roll numbers but do you know what

they really are that's right they are

atomic numbers atomic number is defined

as the number of protons present in the

nucleus of an element this was the major

difference between the modern periodic

table and Mendeleev sporadic table

Mendeleev stable was based on atomic

mass but the modern table is based on

atomic number now you may be wondering

why because the scientist Moseley proved

that atomic number is a more fundamental

property for elements as compared to

atomic mass so the chemical properties

of elements are more related to their

atomic number than their atomic mass

next let's start filling in the elements

in our table so do you know which is the

first element with atomic number one

with just one proton in the nucleus

that's right the correct answer is

hydrogen so let's put the symbol of

hydrogen H in the first box next with

atomic number two we have helium and now

let's go down to the second row so there

we have lithium beryllium boron carbon

nitrogen oxygen fluorine and neon and I

want you to fill up all the way till

element number 20 so that is still

calcium

with every element that you filled in

here the atomic number is increasing by

one so what does that mean one extra

proton is being added in the nucleus now

how is the electron number changing what

do you think that's right the electrons

are also increasing by one because

remember an atom is neutral it has equal

number of protons and electrons and note

we are not concerned about the number of

neutrons right now now let's talk about

the significance of the period or the

row so in our mini periodic table we

have periods from 1 to 4 but remember in

the full periodic table you have it up

till 7 so what is this period number

tell us it tells us the number of

electron shells or electron orbits

present in an atom so we can predict the

number of shells without even drawing

the electronic structure so let's take

some examples hydrogen is in period one

so it has only one shell now if you look

at oxygen it's in period two so it

contains two shells so similarly how

many shells does aluminium have that's

right three shells since it's in period

3 and what about calcium correct for

shells it's in period number four so

with every new period one more shell is

being added now let's verify this by

looking at the electronic configuration

of a few elements let's draw the

electron configuration of hydrogen it

has atomic number one so just one proton

and one electron and as you can see it

has only one shell next let's look at

oxygen it has atomic number eight so

that's eight protons and eight electrons

so if you draw its electron

configuration the first shell will have

two electrons since it can hold maximum

of two and the second shell has

electrons so as you can see oxygen is in

period number two and it has two shells

next we have aluminium with atomic

number thirteen so the electron

configuration is going to be 2 comma 8

comma 3 so aluminium in the third period

has 3 shells you can draw the full

electron configuration or you can write

it in this simple common notation 2

comma 8 comma 3 and let's also look at

calcium which is in the fourth period

with atomic number 20 and as you can see

it's electron configuration is 2 comma 8

comma 8 comma 2 so as expected calcium

in the fourth period has 4 shells now

let's discuss the significance of the

group we always try to group similar

things together so that it's easy for us

a simple everyday life example is the

grocery store where you'll find similar

things grouped together for example

you'll find all the vegetables together

salt and sugar on one side and all the

chocolates in one place now imagine you

walk into the grocery store and

everything is scattered you go crazy

while shopping right similarly in the

periodic table elements having similar

chemical properties are grouped together

now let's take a closer look if you look

at Group one except for hydrogen all the

elements in Group one are metals they

are called alkali metals and they have

similar chemical properties they have

the same valency one now let's look at

Group two once again we see their metals

in this group they are called alkaline

earth metals and they also have the same

valency now let's move ahead to group 17

if you look at this group

it contains nonmetals and they have the

same valency 1 now an interesting

question is why do elements in the same

group

have same valency and similar chemical

properties what do you think well the

answer lies in how the electrons are

arranged in the atom that is the

electronic configuration so let's go

ahead and analyze the electronic

configuration of elements in the same

group let's start with the group 1

elements hydrogen lithium sodium and

potassium they have atomic numbers of 1

3 11 and 19 now let's try to write down

their electronic configuration hydrogen

is simple it just has one electron now

lithium has an atomic number of 3 so

it's going to be 2 comma 1 sodium will

be 2 comma 8 comma 1 and potassium is

going to be 2 comma 8 comma 8 comma 1 so

can you see what these elements have in

common that's right they have just one

electron in their outermost shell so

that's one valence electron so all these

elements have the valency 1 and why do

they have similar chemical properties

because chemical properties depend on

the number of valence electrons which is

same for all these elements now let's

look at Group two here we have beryllium

magnesium and calcium similarly let's

write down their electronic

configurations so beryllium with an

atomic number four is going to be 2

comma 2 magnesium which has an atomic

number of 12 the electron configuration

is going to be 2 comma 8 comma 2 and

calcium which has 20 electrons is going

to be 2 comma 8 comma 8 comma 2 so once

again you can see all these elements

have the same number of valence

electrons which is 2 in this case so

they have the same valency 2 and hence

they show similar chemical properties in

summary we saw that elements belonging

to the same group have the same valency

and similar chemical properties because

they have the same number of valence

electrons

now the group numbering that we saw from

1 to 18 is the new scheme there is an

older scheme that uses Roman numbers and

alphabets a and B let's take a look at

the old scheme as well as we have seen

the new scheme has group numbers from 1

to 18 now let's look at the old scheme

Group 1 has the number 1 a note 1 is

written in Roman numeral and the

alphabet capital e group 2 is two-way

now when we go to group 3 it's tricky

it's going to be 3 B then you have 4 b5

b6 b7 B and groups 8 9 and 10 have the

Roman number 8 then group 11 is 1 b12 is

2b and then when you move on to 13 it's

3 a 4 a 5 a 6 a and group 17 is 7 a and

the last group group 18 has the number 0

the new group numbering scheme is much

easier to remember than the old one but

it's important to know the old one as

well because sometimes it's used now I

can teach you an easy trick to remember

the mapping between the new and the old

scheme basically you have to calcium in

your syllabus element number 20 so if

you take a look you have Group 1 group 2

and then group 13 14 15 16 17 and 18 in

your syllabus you don't have the groups

from 3 to 12 now if you look at the old

scheme so what you have in syllabus is 1

e2 way and then 3 a 4 a 5 a 6 a 7 a and

group 0 so basically only the a groups

are in your syllabus and group 0 which

is the noble gases the B groups and

group 8 are not in your syllabus so I

hope that helps you remember the old

scheme we have a lot of details in our

periodic table now let's go ahead and

add

color you might have seen these colorful

pictures of the periodic table where the

colors represent the different types of

elements for example metals non-metals

noble gases and metalloids so are you

ready to start coloring our periodic

table first let's color the four broad

categories of elements metals non-metals

metalloids and noble gases

now our periodic table looks more

colorful right but you might have seen

some other periodic tables which have

more colors and some different colors in

different groups like this picture here

so let's go ahead and take a look at

some of these groups because they have

some special names the group one

elements are called alkali metals

because these form strong alkalis with

water the group two elements are called

alkaline earth metals because they form

weaker alkalis as compared to the

previous group now moving on to group

thirteen this group is called the boron

family because boron is the first member

in the group similarly group 14 is

called carbon family and then you have

group 15 as nitrogen family and group 16

is called the oxygen family or also

known as Chalco jhin's which means all

forming now group 17 is called the

halogen family and the last group group

18 are known as noble gases or inert

gases till now our focus has been from

element 1 to 20 so till calcium now

let's go ahead and take a look at the

full periodic table in the complete

periodic table we have seven periods or

seven rows and eighteen groups or 18

columns now if you look at period six

and seven you'll notice something

interesting that elements with atomic

number 57 - 71 and 89 203 are put

separately below the periodic table

this is done to compact the periodic

table the elements 57 to 71 are called

lanthanide series because they start

with the element lanthanum these

elements are rare earth elements and

elements from 89 203 are called actinide

series because they start with the

element actinium these are radioactive

elements now let's discuss the merits of

the modern periodic table the merits are

that it corrected the anomalies in

Mendeley its periodic table now how did

it do that because Mendeleev stable was

based on atomic mass but the modern

table is based on atomic number it's

based on the modern periodic law which

states that the properties of elements

are a periodic function of their atomic

number so let's take a look how the

anomalies of Mendeleev stable were

corrected first let's talk about

isotopes isotopes are atoms of an

element having same atomic number but

different mass number they have

identical chemical properties now

isotopes could not fit into Mendeleev

z-- periodic table but in the modern

periodic table they fit in nicely

because they have the same atomic number

so isotopes of an element belong in the

same position as the element and that

makes sense because they have same

chemical properties the second point is

Mendeleev had to make certain exceptions

for some elements but these are fixed in

the modern periodic table for example

the position of cobalt and nickel cobalt

should come first because it has a lower

atomic number as compared to nickel even

though it has a higher atomic mass

because the modern periodic table is

based on atomic number even though

hydrogen is placed in Group one it's

given special treatment many times it's

shown broken off from Group one now why

is that because hydrogen shows prop

that are similar to group 1 elements

that is alkali metals and also group 17

elements that is halogens so since it

shows properties of both these groups

its given special treatment friends I

hope you feel that you have mastered the

modern periodic table now remember

practice makes you perfect so I would

recommend you to draw out our mini

periodic table a couple of times and

learn the first 20 elements now trends

in the periodic table will be covered in

a separate video where we look at how

the properties change across the period

and down the group and do remember to

subscribe to my youtube channel and

follow my facebook page and do check out

my website manoj academy.com friends be

sure to try the quiz and the top three

questions for this topic links are given

below the video thanks for watching