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.