CIE Chemistry (US-0439): Specimen Questions with Answers 36 - 38 of 240

Question number: 36

MCQ▾

Question

What is the chemical formula of Ozone?

Choices

Choice (4) Response

a.

O

b.

c.

d.

Answer

c.

Explanation

is the chemical formula of Ozone.

Question number: 37

MCQ▾

Question

The elements of which group are known as metalloids?

Choices

Choice (4) Response

a.

b.

c.

d.

Answer

d.

Explanation

  • The elements of group have valence electrons. So it is not at all easy for the elements of the group to give electrons in order to achieve octet configuration. At the same time, it is also difficult for the group elements to accommodate four extra electrons in order to achieve octet configuration. Hence they mostly share their valence electrons but do not transfer.

  • Therefore they are known as metalloids as they neither give electrons like metals not accept electrons like nonmetals.

Question number: 38

MCQ▾

Question

Alkali metals form ________ compounds mostly.

Choices

Choice (4) Response

a.

covalent

b.

ionic

c.

organic

d.

Question does not provide sufficient data or is vague

Answer

b.

Explanation

  • Alkali metals form ionic compounds mostly. Alkali metals contain a single electron in their valence shell. Hence it is easy for them to lose one electron and gain stability as per octet rule.

  • Hence, as they form compounds by electron transfer, they are said to be ionic in nature.