Answer:

Explanation:
An element only has <u>one</u> type of atom and cannot be broken down by chemical means.
Let's analyze the answer choices.
1. This has two types of atoms, so it cannot be an element. It has more than one type of atom.
2. This has two types of atoms that are bonded together. It cannot be an element because there is more than one type of atom and the bonds can be broken.
3. This has one type of atoms, so it is an element.
Therefore the best answer choice is 3.
Answer:
1) types of music - independent
performance in doing homework - dependent
person - control
2) period of time - control
number of flowers - dependent
types of rose bushes - independent
Explanation:
Answer:
D: All levels contain the same amount of energy
Explanation:
This is due to how the number of animals also increase as the energy pyramid level decreases.
Hope it helps!
They allowed scientists to study heredity and further develop it