Question

d. Which of these elements have smallest atomic radius?
K19-2,8,9 Li3-2,1 Nall-2,8,1 Be4-2,2​

Answer 1

Explanation:

Answer

19

K,

3

Li,

11

Na,

4

Be

Electronic configurationof the following elements is:

19

K=2,8,8,1

3

Li=2,1

11

=2,8,1Na

4

Be=2,2

4

Be has smallest atomic radius because

19

K,

3

Li,

11

Na are present in same group 1 but Be is present in group 2. According to the trend, as we move from left to right atomic size of an atom decreases. Due to a large positive charge on the nucleus, the electrons are pulled closer to the nucleus, and the size of the atom decreases.