1. we used to represent an element. a. chemical formula
b. symbol

2. the chemical formula of a molecule shows the.
a. number of atoms contained in the molecule.
b. chemical properties of the molecule.
c. number and kind of atoms contained in the molecule.

3. which of the following is an atom.
a. K
b. CO
c. H2O
d. HI

4. which of the following is a molecule.
a. He
b. N
c. Ar
d. CO

Does the energy in a solid increase or decrease when changing to a liquid?

6. what does the symbol ah stand for? o one calorie given off by a reaction the specific heat of a substance the heat capacity of a substance the heat of reaction for a chemical reaction

The human activities in two locations are described below: location a: rampant use of plastic containers location b: excessive use of pesticides and fertilizers which statement is most likely true? location a will have poor air quality because plastic is biodegradable. location a will experience water scarcity because plastic absorbs moisture. the population of honeybees will increase in location b because production of crops will increase. the population of fish in location b will decrease because the water is contaminated.