Chemistry Review 1

An atom of carbon, with atomic number 6, always has:

• More than 6 neutrons

• Six protons in its nucleus

• An atomic mass of six

• Six energy levels

What state of matter is found in the universe and has the most energy?

• gas

• liquid

• density

• plasma

An atom has 9 protons, 9 electrons and 10 neutrons. What is its mass number?

Which one of the below represents a chemical change?

• Freezing

• Melting

• Burning

• Evaporating

All of the below are physical changes except:

• Change in size

• Change in temperature

• Change in color

• Change in shape

When an atom has an equal number of protons and electrons, it is a _______ atom.

• postitive

• negative

• neutral

• dense

A property that is observed by your senses.

Dot diagrams are used to represent:

• Mass number

• Structure of the atom

• Protons

• Valence electrons

Which of the below statements explains the Law of Conservation of Mass in a chemical reaction?

• The mass of the products is greater than the reactants.

• The mass of the reactants is greater than the products.

• The mass of the reactants is equal to the mass of the products.

• There is no relationship between the mass of reactants and products.

Which of the following substances would be least likely to dissolve in water?

• A non-polar molecule like methane

• An ionic compound, such as sodium chloride (table salt)

• A polar molecule like glucose

• A polar molecule like ammonia