Trends in the periodic table

Question 1

Atomic Size

Answer 1

As you go down each group in the periodic table, the size of an atom increases because they are gaining more shells

As you go across a period in the periodic table, the size of an atom decreases because you add protons that weigh a lot and can be pulled into the forces from the nucleus making it smaller.

Question 2

Ionization Energy

Answer 2

Ionization energy is the energy required to remove an electron from a neutral atom

It is easier to remove electrons from larger atoms, because they are further from the attractive forces of the nucleus

Larger atoms have lower ionization energies, and smaller atoms have higher ionization energies

Ionization energy decreases down a group, and increases across a period

Question 3

Reactivity

Answer 3

The larger a metal is, the easier it is for it to give up electrons, and the more reactive it is.

The smaller a non-metal is, the easier it is to pull in electrons due to the proximity to the oppositely charged nucleus. Therefore, the smaller a non-metal is, the more reactive it is.

Question 4

Electron Affinity

Answer 4

Electron affinity is a measure of how much an element loves electrons

If an element has a high electron affinity, it tends to hold on to its electrons, and gain them in chemical reactions (non-metals). This tends to happen with smaller atoms.

If an element has a low electron affinity, it tends to give away its electrons, and not hold on to them (metals). This tends to happen with larger atoms.

Electron affinity tends to decrease down a group, and increase across a period