Answer:
b
Explanation:
Hydrocarbons provide 84% of the world's energy, but they are non-renewable. Hydrocarbons are the most economic form of energy.
Answer: C) Gold
Explanation:
Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: Gold
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass. It can be decomposed into simpler constituents using chemical reactions. Example: water
, butanal , and propene
For example:
Thus the element gold can not be broken down by a chemical change.
Alpha particles; they can be blocked with a sheet of paper