Chemistry

Question 1

1. an alkaline Earth metal and an essential mineral needed by the body to maintain strong bones and teeth.

Answer 1

calcium

Question 2

2. is a greenhouse gas that is a natural waste product of human and animal exhalation.

Answer 2

Carbon dioxide

Question 3

_________, or trioxygen, is a molecule that is formed naturally in the stratosphere through the interaction of ultraviolet sunlight
and molecular oxygen. Ground-level _____ is an air pollutant that is formed by volatile organic compounds and nitrogen
oxides.

Answer 3

Ozone

Question 4

4. ___ is the lightest solid and metal on the periodic table. It is also used in the production of batteries

Answer 4

Lithium

Question 5

5. A is the physical combination of two or more pure substances. Air and seawater are examples of mixtures.

Answer 5

mixture

Question 6

6. are negatively-charged subatomic particles that are found in the outer shells of the atom.

Answer 6

Electrons

Question 7

7. The two major elements that make up the atmosphere are ________. The are 78% and 21%, respectively.

Answer 7

nitrogen (78%) and oxygen (21%).