Topic 2

Question 1

Describe how chlorine’s position in the periodic table is related to its electron arrangement.

Answer 1

Cl has 7 valence electrons and is in group 7;

Accept “group 17” as suggested by IUPAC.

Cl has 3 occupied (electron) shells/energy levels and so is in period 3;

Question 2

What is the total number of valence electrons in 
C
H
3
CO
O
−
?

A. 16

B. 22

C. 23

D. 24

Answer 2

D

Question 3

Which statements about the chlorine free radical are correct?

I. It has 18 electrons.

II. It is an uncharged species.

III. It is formed by homolytic fission.

A. I and II only

B. I and III only

C. II and III only

D. I, II and III

Answer 3

C

Question 4

Which are correct statements about the emission spectrum of hydrogen in the visible region?

I. The red line has a lower energy than the blue line.

II. The lines converge at longer wavelength.

III. The frequency of the blue line is greater than the frequency of the red line.

A. I and II only

B. I and III only

C. II and III only

D. I, II and III

Answer 4

b