1st Semester Science Exam Review #1

1st Semester Science Exam Review #1

Multiple Choice

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

Multiple Choice

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

• 30

• 20

• 19

• 9

Multiple Choice

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

• gas

• liquid

• density

• plasma

Multiple Choice

Which one of the below represents a chemical change?

• Freezing

• Melting

• Burning

• Evaporating

Multiple Choice

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

• big

• negative

• small

• nuetral

Multiple Choice

All of the below are physical changes except:

• Change in size

• Change in temperature

• Change in color

• Change in shape

Fill in the Blank

A property that is observed by your senses.

Multiple Choice

Dot diagrams are used to represent…..?

• Mass number

• Structure of the atom

• Protons

• Valence electrons

Multiple Choice

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

• Mass of the product is greater than its reactants

• The mass of the reactant is greater than the product

• The mass of the product is equal to the mass of the reactant

• There is no relationship between the mass of the product and reactant

Fill in the Blank

A substance formed when two or more

elements are chemically bonded together.

Multiple Choice

A solution that contain a small amount of solute compared to solvent is described as:

• Concentrated

• Saturated

• Dilute

• Homogenous

Fill in the Blank

A substance that tastes sour and has a pH below 7

Multiple Choice

A bond that forms between atoms when they gain or lose (transfer) electrons is?

• Atomic

• Covalent

• Ionic

• Shared

Fill in the Blank

A change of state from gas to liquid.

Multiple Choice

What does it mean to say that water has covalent bonds?

• Water sticks to ice

• Water's atoms don't share electrons equally

• water's atoms share electrons equally

• Water is found in the polar caps

Multiple Choice

The melting of wax is a physical change, yet the burning of wax is a chemical change. What is the essential difference between the physical change and the chemical change of wax in a burning candle?

• Meltedwax is a different phase of matter than solid wax

• A high temperature is needed to burn wax than to melt wax

• Melted wax can be seperated into other substances, while solid wax cannot

• The burning of wax forms new compounds, while the melting of wax does not

Multiple Choice

Water is said to be the universal solvent because it

• covers most of the planet

• can dissolve so many different solutes

• is a nonpolar molecule

• is found everywhere in the universe

Multiple Choice

Which of the following substances would cause a color change in the phenolphthalein, an indicator that turns from clear to pink in the presence of a substance with a pH greater than 7?

• NaCL

• H2O

• KOH

• HF

Multiple Choice

Oil does not dissolve in water because it is made of

• polar molecules

• hetergenous mixtures

• different molecules

• nonpolar molecules

Multiple Choice

Most of the time the oxidation number of metals are

• covalent

• positive

• negative

• neutral

Multiple Choice

The maximun number of electrons in the 2nd energy level of an atom is

• two

• eight

• ten

• four

Multiple Choice

Look at the following equation:
 $4Fe+3O_2\rightarrow2Fe_2O_3$  

• synthesis

• decomposition

• single replacement

• double replacement

Multiple Choice

On Monday, the custodian places an air freshner in the bathroom. Over the next several days it shrinks. Which of the following statements best describes this change

• The disk is undergoing a chemical change

• The disk is undergoing a physical change

• The disk is undergoing both a chemical and physical chage

• The disk is undergoing neither a physical nor a chemical change

Multiple Choice

Which pair of elements is MOST similar

• Na and P

• B and H

• Li and K

• Ne and O