Exam 1

Question 1

Density Equation

Answer 1

D = (mass g) / (volume mL)

Question 2

Empirical Formula

Answer 2

lowest whole number ratio of elements in the compound

Question 3

Molecular Formula

Answer 3

number atoms of each type found in a molecule

Question 4

True or False: A substance’s boiling point and condensation points occur at the same
temperature.

Answer 4

True

Question 5

True or False: As the temperature of a substance decreases, the atoms’ speed, on average, decreases

Answer 5

True

Question 6

As chemical reactions occur, describe how do the number of protons, electrons, and neutrons change.

Answer 6

Electrons are gained or lost during almost all of the chemical reactions
including oxidation-reduction reactions. The # of protons does not change in these types of chemical reactions. The # of neutrons can vary when discussing different isotopes of an element.
The identity of an element changes when the # of protons change

Question 7

86
Sr
38

Answer 7

Protons: 38
Mass #: 86
Electrons: 38
Neurons: 48

Question 8

What does the phrase “aqueous calcium chloride” mean?

Answer 8

Calcium and chloride ions dissolved in water.

Question 9

Rutherford’s model of the atom suggests that:

Answer 9

a small number of alpha particles are strongly deflected by the positively charged nucleus.

Question 10

Coulomb’s Law

Answer 10

rationalize relative melting points of certain salts

Question 11

Coulomb’s Law Explained

Answer 11

-the larger the ionic charge the greater the magnitude of attraction between the ions,
-the smaller the distance between ions the greater the magnitude of attraction between ions
-the greater the magnitude of attraction the more energy needed to separate the ions upon melting thus higher the melting point temp

Question 12

lower density = floats

Answer 12

-due to molecules orientation leads to more space between molecules than in water, so fewer H2O particles per volume in solid