How Does The Periodic Table Work | Properties of Matter | Chemistry | FuseSchool

Summary

The video script delves into the periodic table's structure, highlighting its seven periods and 18 groups. It explains how elements are arranged by atomic number and the significance of periods and groups in determining an element's electron shell and outer electron count. The script explores periodicity trends across periods, such as the transition from metals to non-metals, decreasing atomic radius, and increasing ionization energy and electronegativity. It also discusses trends down the groups, including increased metallic character, atomic radius, and a shift in reactivity for metals and non-metals. Special attention is given to group one (Alkali Metals), group 17 (Halogens), and group 18 (Noble Gases), detailing their unique properties and reactivity.

Takeaways

• 🔍 The periodic table is organized into 7 periods (horizontal rows) and 18 groups (vertical columns).
• 🔬 Elements are arranged by increasing atomic number, which corresponds to the number of protons in the nucleus.
• 🌐 The period number indicates the electron shell being filled, while the group number (second number if there are two) indicates the number of valence electrons.
• 🔋 Chemical reactions involve the movement of electrons, and elements within the same group have similar chemical properties due to having the same number of outer shell electrons.
• 📉 As you move from left to right across a period, elements transition from metals to non-metals, atomic radius decreases, first ionization energy increases, and electronegativity increases.
• 📈 Going down a group, elements exhibit increasing metallic character, atomic radius increases, and first ionization energy decreases.
• 🔑 Group 1 (Alkali Metals) becomes more reactive as you move down the group due to easier electron loss.
• 💨 Group 17 (Halogens) becomes less reactive as you move down because of a stronger attraction for incoming electrons.
• 🏔 Group 18 (Noble Gases) are very unreactive because they have a full outer shell of electrons, and their densities and boiling points increase as you move down the group.

Q & A

What are the seven rows in the periodic table called?

The seven rows in the periodic table are called periods.

How many columns, also known as groups, are there in the periodic table?

There are 18 columns, also known as groups, in the periodic table.

What determines the arrangement of elements in the periodic table?

The elements in the periodic table are arranged according to their atomic number, which is the number of protons in their nucleus.

What does the period number of an element indicate about its electron configuration?

The period number of an element indicates the electron shell that is being filled.

What is the connection between an element's group and the number of electrons in its outer shell?

The group an element is in gives the number of electrons in the outer shell of an atom of that element.

What is the electronic configuration for carbon, which is in Period 2 and Group 14?

The electronic configuration for carbon is 2, 4.

As you go from left to right across a period in the periodic table, what happens to the atomic radius?

As you go from left to right across a period, the atomic radius decreases due to the increasing attraction of the nucleus for the electrons.

What is the trend in first ionization energy as you move across a period in the periodic table?

The first ionization energy increases as you move from left to right across a period in the periodic table.

How do the properties of elements change as you go down a group in the periodic table?

As you go down a group, the elements become more metallic, with an increase in atomic radius and a decrease in first ionization energy.

Why do elements in Group 18, the noble gases, have very unreactive chemical properties?

Elements in Group 18 have very unreactive chemical properties because they have a full outer shell of electrons, making them stable and less likely to participate in chemical reactions.

What happens to the reactivity of metals as you go down Group 1 in the periodic table?

As you go down Group 1, the metals become more reactive because it is easier for them to lose their outer shell electron, which is further from the positively charged nucleus.

Outlines

00:00

🔬 Understanding the Periodic Table

The periodic table is structured with seven periods and eighteen groups, organizing elements by atomic number, which corresponds to the number of protons in the nucleus. Elements in the same period have electrons filling the same shell, as illustrated by sodium (Na) and chlorine (Cl) both in Period 3. The group number indicates the number of valence electrons, which is crucial for understanding chemical properties. Elements within the same group exhibit similar chemical behaviors due to having the same number of outer shell electrons. Trends across periods show a transition from metals to non-metals, a decrease in atomic radius due to increased nuclear charge, and an increase in first ionization energy and electronegativity.

Keywords

💡Periodic Table

The Periodic Table is a tabular arrangement of chemical elements organized on the basis of their atomic number, electron configurations, and chemical properties. It consists of seven periods (rows) and 18 groups (columns). The video script explains that elements are arranged according to their atomic number, which is the number of protons in the nucleus. The Periodic Table is crucial for understanding the trends and properties of elements, as it shows how elements' characteristics change across periods and down groups.

💡Atomic Number

Atomic number refers to the number of protons in the nucleus of an atom, which is unique for each element. In the context of the video, it is mentioned that elements in the Periodic Table are arranged according to their atomic number. This arrangement is fundamental because it determines the element's position in the table and its chemical behavior.

💡Electron Shell

An electron shell is a region surrounding the nucleus of an atom where electrons are located. The video script uses the term to explain that the period in the Periodic Table indicates the electron shell that is being filled. For instance, sodium (Na) in Period 3 has its third shell being filled, as indicated by its electronic configuration 2, 8, 1.

💡Electronic Configuration

Electronic configuration describes the arrangement of electrons around the nucleus of an atom. The video script uses this term to illustrate how elements in the same period have the same number of electron shells being filled. For example, both sodium and chlorine have electronic configurations that reflect their third shell being filled, despite being in different groups.

💡Group

A group in the Periodic Table is a column that contains elements with similar chemical properties. The video script explains that the group number gives the number of electrons in the outer shell of an atom, which is crucial for understanding an element's chemical behavior. For example, carbon in Group 14 has four electrons in its outer shell, as indicated by its electronic configuration 2, 4.

💡Chemical Properties

Chemical properties are the characteristics that substances display during chemical reactions. The video script emphasizes that elements in the same group have similar chemical properties because they have the same number of outer shell electrons. This similarity leads to consistent patterns in how elements react.

💡Periodicity

Periodicity refers to the trend in properties across each period of the Periodic Table. The video script describes how properties change as you move from left to right across a period, such as elements changing from metals to non-metals, a decrease in atomic radius, and an increase in first ionization energy and electronegativity.

💡Atomic Radius

Atomic radius is the distance from the nucleus to the outermost shell of an electron. The video script notes that there is a decrease in atomic radius across a period because more protons in the nucleus pull the electrons closer. This concept is essential for understanding how elements' sizes change with their position in the Periodic Table.

💡First Ionization Energy

First ionization energy is the energy required to remove the outermost electron from an atom. The video script mentions that this energy increases across a period because it becomes harder to remove an electron as more protons are present in the nucleus, pulling the electrons closer.

💡Electronegativity

Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons. The video script explains that electronegativity increases across a period, meaning that atoms become more attracted to the electrons in a chemical bond as you move from left to right.

💡Metallic and Non-metallic Properties

Metallic properties are characteristics displayed by metals, such as good electrical and thermal conductivity, malleability, and reactivity by losing electrons. Non-metallic properties are displayed by non-metals, which are typically poor conductors of heat and electricity, brittle, and reactive by gaining electrons. The video script discusses how elements become more metallic or non-metallic as you move down a group in the Periodic Table.

Highlights

The periodic table is organized into seven periods and 18 groups.

Elements are arranged by atomic number, which is the number of protons.

The period indicates the electron shell being filled.

The group number corresponds to the number of valence electrons.

Elements in the same group have similar chemical properties due to the same number of outer shell electrons.

Chemical reactions involve the movement of electrons.

Trends across a period include a change from metals to non-metals.

Atomic radius decreases from left to right across a period.

First ionization energy increases as you move across a period.

Electronegativity increases from left to right in a period.

Elements become more metallic as you go down a group.

Metals are reactive due to their tendency to lose electrons.

Non-metals are reactive due to their tendency to gain electrons.

Atomic radius increases as you go down a group.

First ionization energy decreases down a group.

Group 1 consists of alkali metals, which become more reactive as you go down.

Group 17, the halogens, become less reactive as you go down.

Group 18, the noble gases, are unreactive due to their full outer electron shells.

Densities and boiling points of noble gases increase down the group.

Transcripts

Trends in the periodic

table the periodic table consists of

seven rows called periods going across

and 18 columns called groups going down

the elements in the periodic table are

arranged according to their atomic

number which is the number of protons in

their

nucleus so what do the period and the

group show well the period shows the

element's electron shell that is being

filled for example sodium na in Period 3

Group 1 has the electronic configuration

2

81 whereas chlorine CL also in Period 3

but in group 17 has the electronic

configuration

287 in both cases it is the third shell

that is being

filled can you see a connection between

the group and element is in and the

number of electrons in its outer shell

note that if the group has two numbers

we take the second

number pause the video while you

think the group an element is in gives

the number of electrons in the outer

shell of an atom of that element now

pause the video again and write the

electronic configuration ation for

carbon atomic number six Period 2 and

group

14 the electronic configuration for

carbon is

24 did you get it right chemical

reactions are to do with the movement of

electrons so as all elements in a

particular group have the same number of

outer shall electrons they have similar

chemical

properties let's take a look at the

trends of across the periods periodicity

is the trend in properties across each

period let's go from left to right

across a period what do you

notice first of all elements change from

metals to

non-metals also note that there is a

decrease in atomic radius this is

because more protons are in the nucleus

which pull the electrons closer in there

is also an increase in first ionization

energy which is the energy needed to

remove the outermost electron and an

increase in electro negativity which

means the attraction of a bonded atom

for the pair of electrons in a calent

bond now let's look at the trends as we

go down a

group notice that the elements become

more metallic this is clearly seen in

group 14 where carbon in Period 2 is a

non-metal but lead in Period 6 is a

metal by the way do you remember that

metals are elements that react by losing

electrons and non-metals are elements

reacting by gaining

electrons also going down the group

there is an increase in atomic radius

this means that an extra shell of

electrons is added for each successive

element however there is a decrease in

first ionization energy which as noted

before is the energy needed to remove

the outermost

electron there are three groups of the

periodic table that are usually studied

group one The Alkali Metals Group 17

called the halogens and group 18 called

the noble gases as we go down group one

the metals become more reactive this is

because metals react by losing electrons

and it is easier to lose the outer shell

electron the further it is from the

positive

nucleus as we go down Group 17 the

nonmetals become less reactive because

non-metals react by gaining electrons

and the fewer shells the greater

attraction for the incoming

electron and in group 18 elements have a

full outer shell of electrons and so are

very

unreactive their densities and boiling

points increase on going down the group