BECE Matter, Elements, and Compounds 3

Question 1

How can a mixture be distinguished from a compound?

Accepted Answer

Mixtures can be separated by physical means

Answer

Mixtures can be separated by physical methods like filtration or magnetism, while compounds require chemical reactions to separate.

Question 2

Which of the following is a heterogeneous mixture?

Accepted Answer

Soil

Answer

Soil is heterogeneous because its composition is not uniform — different particles of sand, clay, and organic matter are visible.

Question 3

What method would best separate a mixture of iron filings and sand?

Accepted Answer

Using a magnet

Answer

A magnet attracts iron filings but not sand, making magnetic separation the most effective method.

Question 4

Air is classified as a mixture rather than a compound because:

Accepted Answer

Its components can be separated and their proportions vary

Answer

Air has variable composition (proportions of N₂, O₂, CO₂, etc. vary) and its components can be physically separated.

Question 5

Which separation technique works best for recovering dissolved salt from salt water?

Accepted Answer

Evaporation

Answer

Evaporating the water leaves behind the dissolved salt as solid crystals.

(BECE) Basic Education Certificate Examination Practice Test