Answer: The answer for this is Compound.
Explanation: A matter is something which occupies space and has some mass.
Elements are defined as the smallest substances which cannot be broken down into another substance by any chemical means.
A compound is a defined as a substance composed of two or more different elements when they combine chemically in definite proportion. For example:
is named as carbon dioxide and is a compound made by combining carbon and oxygen in a fixed ratio of 1 : 2
So, the answer to the given question is compound.
Answer: b) positron
Explanation:
The antiparticle or the antimatter counterpart of the electron is called positron.
The positron has an electric charge of +1 e and same mass as an electron. When a positron collides with an electron, annihilation takes place.
Below is an attachnent that further explains this
Density = Mass/Volume => Mass = Density*Volume => Mass = 3g/ml*10ml =30g