Periodic trends and ions

As you move down a group, atomic radius increases because

• you add more and more neutrons.

• you add more and more protons.

• you add more and more shells (energy levels).

• you add more atomic mass.

Which element in Period 6 has the lowest ionization energy?

• Rn

• Cs

• Os

• Tm

As you move across the periodic table from left to right, the atomic radius decreases. Why?

• The number of protons increases, so attraction to electrons increases.

• The number of energy levels increases.

• The number of electrons increases.

• The atomic mass increases.

Francium (Fr) has the lowest ionization energy in Group 1 because

• it has the smallest number of valence electrons.

• it has the greatest atomic mass.

• it has the greatest number of protons, so it attracts its electrons the strongest.

• its 1 valence electron is very far from the nucleus, so little energy is needed to remove it.

Atoms that have a high electronegativity, _______________.

• give up their electrons more easily.
• hold on to their electrons more tightly.
• have more electron shells.

Which atom in Period 4 has the largest atomic radius?

• K

• Kr

• Fe

• Fe

The element with the largest electronegativity in the halogen group is

• At.

• F.

• Cl.

• Br.

Ions are formed when atoms gain or lose ___.

• electrons

• protons

• neutrons

• atomic mass

Ions are: 

• atoms with a positive or negative charge
• atoms with no charge
• atoms with ONLY a positive charge
• atoms with ONLY a negative charge

When an atom loses an electron, it becomes a(n) _____________ ion.

• positive

• negative

• neutral

• polyatomic