8. Periodic table and periodicity

Question 1

periodicity

Answer 1

repeating trends in physical and chemical properties

Question 2

1st Ionisation Energy

Answer 2

energy required to remove 1 mole of e- from 1 mole of atoms in gaseous state
X(g) → X+(g) + e-

Question 3

2nd Ionisation Energy

Answer 3

energy required to remove 1 mole of e- from 1 mole of atoms in gaseous state

Question 4

factor affecting IE

Answer 4

• nuclear charge
  more proton in nucleus
  → more (+ve) charged nucleus
  → stronger attraction for e-

ATOMIC RADIUS

• e- is further from nucleus
• easier to remove

SHIELDING

• e- in inner shells exerts a repelling effect on electron in outer-shell
• reduces pull of nucleus on outer e-

Question 5

IE decreases down a group

Answer 5

• element down a group have extra electron shells