Chemistry: The Periodic Table

Overview of the Periodic Table

The Periodic Table is a tabular arrangement of all known chemical elements based on their atomic number, electron configuration, and recurring chemical properties.
Elements in the table are organised into groups (vertical columns) and periods (horizontal rows).
Each element has a symbol, atomic number and a relative atomic mass. The atomic number determines the position of an element on the table.
The table is divided into metals on the left, non-metals on the right and metalloids in a zig-zag line separating metals and non-metals.
The Periodic Table is a crucial tool for chemists, providing a handy reference to the properties and behaviours of various elements.

Understanding Groups and Periods

Groups in the Periodic Table contain elements with the same number of electrons in their outer shell (valence electrons). This number is also the group number.
Every element in a group shows similar chemical properties due to the same number of electrons available for bonding.
Periods contain elements with the same number of electron shells. This number corresponds to the period number.
Moving from left to right in a period, the elements increase in reactivity until reaching Group 0. These elements, called the Noble Gases, are stable and unreactive as they have full outer shells of electrons.

Transition Metals and Block Elements

The transition metals are the elements in Groups 3-12. They are known for being good conductors of heat and electricity, and their high melting and boiling points.
The lanthanides and actinides, also known as f-block elements, are located at the bottom of the periodic table. They have variable oxidation states and are often associated with radioactive properties.

Reactivity Trends in the Periodic Table

In Group 1 (alkali metals), reactivity increases as you go down the group. This is due to the outer electron being further from the nucleus and being more easily lost, leading to a positive ion.
In Group 7 (halogens), reactivity decreases as you go down the group. This is because the larger atoms have greater difficulty in attracting and holding an extra electron to reach a full outer shell.
Group 0 elements are unreactive due to their full outer electron shells, making them stable.

Remember, understanding the structure of the Periodic Table and the properties of its elements is key to building a strong foundation in chemistry. Highlight key terminology and properties for each group and period while revising. This will help you to better understand and remember how different elements behave.