Answer:
The Answer is (C)
Explanation:
Reasons are when anything cools or condenses it tends to be more solid, and solids don't move.
Explanation:
A change that does not cause any change in chemical composition of a substance is known as a physical change.
For example, mass, density, volume etc are all physical changes.
On the other hand, a change that brings change in chemical composition of a substance is known as chemical change.
For example, combustion, toxicity, reactivity etc are all chemical changes.
Hence, following statements are identified as chemical or physical changes as follows.
(a) Oxygen gas supports combustion : Chemical change
(b) Fertilizers help to increase agricultural production : Chemical change
(c) Water boils below
on top of a mountain : Physical change
(d) Lead is denser than aluminum : Physical change
(e) Uranium is a radioactive element : Chemical change
Surface over which the air mass was formed.
Answer:
Reactants starts the chemical reaction and gives right to the product either by thermal decomposition or in the presence of a catalyst.
Explanation:
Reactants and products contain the same atoms, but they are rearranged during the reaction, so reactants and products are different substances.