WCH11 June 2022

11. Some physical properties of five substances are shown. The letters are not element symbols.

(a) Which of these substances could be metals?​​ 

(1)​​ 

A​​  N only​​ 

B​​  L and M only​​ 

C​​  M​​ and N only​​ 

D​​  L, M and N only​​ 

ANSWER

C​​  M and N only​​ 

Analysis of Option/Explanation

For metals, it is mandatory that in solid state, it will definitely have good electrical conductivity. Hence, element M and N are metals. Therefore, option is the correct answer.

(b) Which substance has properties showing that it changes from a molecular structure to ions when it dissolves in water?​​ 

(1)​​ 

A ​​ L​​ 

B​​  M​​ 

C​​  P​​ 

D​​  Q

ANSWER

D​​  Q

Analysis of Option/Explanation

When in molecular structure it will not conduct​​ electricity in solid and liquid state but when reacts with water then it will conduct electricity, i.e. having ions. Hence, option D is the correct answer highlighting element Q.