1. Which of the following has a positive charge?

(A) proton

(B) neutron

(C) anion

(D) electron ANS = A

2. How many electrons are there in the valence shell of the O2–ion?

A 2

B 8

C 10

D 16

3. What is the formula of the compound formed between magnesium and oxygen?

A MgO

 B Mg2O2

C Mg2O3

D MgO2 


3. Which one of the following statements concerning elements in the Periodic Table is

correct?

A Elements of the same group all have the same number of electrons in the outermost

 occupied electron shell.

B Elements of Group 16 occur as cations in ionic compounds.

C Oxides of elements in Groups 16 and 17 are basic.

D The halogens are all gases at room temperature.