Question

Explain how Li and Mg have very similar atomic radii. This leads to quite a few similarities between the properties of these two elements. What is the relationship called?

Answer 1

Part 1: Relation between atomic radii of Lithium $\left(\mathrm{Li}\right)$ and Magnesium $\left(\mathrm{Mg}\right)$:

• Atomic radii mean the distance between the nucleus of an atom and electrons in the valence shell.
• On the periodic table, the size of an atom decreases across a period and increases with the group. Because of the diagonal position of Lithium and Magnesium, their atomic radii are moreover similar.

Part 2: Similar properties between Lithium (Li) and Magnesium (Mg):

• Both are s-block elements.
• They have a similar Atomic size.
• Electronegativity is moreover similar.
• Both are metals.
• They form oxide when they get react with Oxygen$\left(\mathrm{O}\right)$.

Part 3: Relationship between them:

• Diagonal relationships occur between the atoms that exist diagonally adjacent in the periodic table.
• There is a similarity between the first element of the period $2$ and the second element of the period $3$.
• This relation is called a diagonal relationship.
• This diagonal relationship is seen between Lithium and Magnesium.