Answer:

Explanation:
The temperature and amount of gas are constant, so we can use Boyle’s Law.

Data:

Calculations:

Answer:
Stars shine because they are extermly hot of light .The source of their energy is niclear reactions going on deep inside the stars.
Explanation:
well excuse the "s" at the end
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