Chemistry Quiz

Chemistry is defined as

• a branch of knowledge which produces chemicals

• the branch of science which deals with changes in matter

• the oldest branch science.

• the branch of science which makes physics and biology clearer.

Scientific approach to discoveries follows the order which includes

• observation, hypothesis, and results

• experiments, hypothesis and results

• further experiments and problems solving.

• theory, negative and positive results and experiments.

Chemical hypothesis is different from chemical law in that

• hypothesis is a reasonable explanation to observations made while law is a statement from a scientist.

• hypothesis is a reasonable explanation to observations while law is a statement which confirms the hypothesis after extensive tests.

• hypothesis is not reasonable while law is reasonable.

• none of the above.

Chemical changes around us includes all except

• rusting of iron nails

• sieving

• fading of coloured cloth

• decomposing of green leaves in a compost

One of these professions has no need for chemistry

• Miners

• Engineers

• Philosophers

• Geologists

The simplest unit of water that retains its properties is called

• an atom

• an element

• an hydroxide

• a molecule

Which of the following basic particles with the smallest mass makes up an atom

• a proton

• a neutron

• an x- particle

• an electron

The following are physical changes except

• melting of candle wax

• Dissolving common salt in water

• Freezing of water

• Rotting of leaves.

Which of the following is not a molecule of the same element.

• O2

• P4

• S8

• CO2

The atomicity of O3 is

• 1

• 2

• 3

• 4