Unit 1: Covalent Radius

Question 1

Define covalent radius

Answer 1

a measure of the size of an atom

Question 2

What is C.R meausred in?

Answer 2

pm or Anstrom

Question 3

What happens to C.R across a period?

Answer 3

C.R decreases

Question 4

What happens to C.R down a group?

Answer 4

C.R increases

Question 5

Why does C.R decrease across a period?

Answer 5

When the atomic number increases the number of protons increase.
More protons = stronger nuclear charge.
Stronger nuclear charge = more electrons attracted to the nucleus.
More attraction = tighter pull
Tighter pull = smaller atom

Question 6

Why does C.R increase down a group?

Answer 6

There are more full occupied shells.
More occupied shells = more shielding.
More shielding = less attraction to the nucleus
Less attraction = larger atom