Exam 1 Review

Question 1

Classify the basic forms of matter.

Answer 1

Solid, liquid, gas.

Question 2

Identify the types of pure substances.

Answer 2

Elements and compounds.

Question 3

Physical property.

Answer 3

Observed without changing the composition or identity of a substance.

Question 4

Physical change.

Answer 4

Produces a recognizable difference in the appearance of a substance, without causing any change to its composition.

Question 5

Example of physical changes (simple).

Answer 5

Phase change

Question 6

What are examples of physical properties?

Answer 6

Conductivity, boiling point, density, temperature, volume, solubility.

Question 7

What are examples of chemical properties?

Answer 7

Flammability, oxidation state, acidity.

Question 8

Define intensive properties.

Answer 8

Properties of matter that are independent of quantity.

Question 9

Examples of intensive properties.

Answer 9

Color, melting point, boiling point, don’t ask me about density.

Question 10

Examples of extensive properties.

Answer 10

Mass, volume.

Question 10

Define extensive properties.

Answer 10

Properties of matter that are dependent on the quantity.

Question 10

Significant figure rules.

Answer 10

All nonzero digits are significant. Zeros located between nonzero digits are significant. Trailing zeros are significant if the number has a decimal point. Zeros to the left of the nonzero digit are insignificant.

Question 11

Significant figure rules in addition/subtraction.

Answer 11

The result cannot have greater significance than any of the quantities that produced the result.

Question 11

Accuracy

Answer 11

Degree of agreement between the true value and measured value.

Question 11

When adding or subtracting in scientific notation…

Answer 11

Convert both numbers to standard form.

Question 11

Significant figure rules in multiplication/division.

Answer 11

The result should have the same amount of significant figures as the number with the least significant figures.

Question 11

Conversion between Celsius and Fahrenheit.

Answer 11

F = 1.8 x C + 32

Question 11

Precision

Answer 11

Degree of agreement between all measures values.

Question 11

Density formula.

Answer 11

d = m / v (g/ml or g/L)

Question 12

Define specific gravity, give the formula.

Answer 12

Specific gravity is the ratio of the density of a substance to the density of water.
Specific gravity =
density of object / density of water

Question 13

What element is most present in the human body?

Answer 13

Oxygen.

Question 14

Groups vs. Periods

Answer 14

Groups are vertical! Periods are horizontal.

Question 15

A neutral atom has…

Answer 15

The same number of electrons and protons.

Question 16

Atomic number (Z).

Answer 16

The number of protons in an atom.

Question 17

Mass number (A).

Answer 17

Sum of the protons and neutrons in an atom.

Question 18

The letter for the atomic number is...

Answer 18

Z

Question 19

The letter for the mass number is...

Answer 19

A

Question 20

Define isotopes.

Answer 20

Atoms of the same element with different numbers of neutrons, therefore a different mass number.

Question 21

Do isotopes have identical chemical properties?

Answer 21

Yes.

Question 22

Atomic mass is the...

Answer 22

Weighted average of all the isotopes of a specific element.

Question 23

Steps to find atomic mass, given mass number of isotopes and percentages.

Answer 23

1. Convert percentages to decimals (e.g. 75.77% --> 0.7577) 2. Multiple the decimal by the mass of the associated isotope (e.g. 0.7577 x 35 = 26.5) 3. Do this for all the given isotopes. 4. Add them all together!

Question 24

Dalton's Atomic Theory (postulates).

Answer 24

1. TRUE All matter is made up of atoms. 2. An atom cannot be created, destroyed, or converted to another kind of atom. 3. Atoms of a particular element have identical properties. 4. TRUE Atoms of different elements have different properties. 5. TRUE Atoms of different elements combine in simple, whole-number ratios to form compounds. 6. TRUE Chemical change involves joining, separating, or rearranging atoms.

Question 25

What postulates are still regarded as true?

Answer 25

1,4,5,6.

Question 26

What experiment provided proof of electrons?

Answer 26

Cathode-ray.

Question 27

What experiment provided proof of the nucleus?

Answer 27

Gold-foil.

Question 28

Law of Conservation of Mass.

Answer 28

In a chemical reaction, matter is neither created nor destroyed. The total mass of the substances involved does not change.

Question 29

Law of Definite Proportions

Answer 29

All samples of a given compound have the same proportions of their constituent elements.

Question 30

Law of Multiple Proportions

Answer 30

When two elements form two different compounds, the masses of the constituent elements can be expressed as a ratio of whole numbers.

Question 31

Elements of the same... have similar properties.

Answer 31

Group.

Question 32

Metals tend to...

Answer 32

lose electrons.

Question 33

Nonmetals tend to...

Answer 33

gain electrons.

Question 34

Metalloids have...

Answer 34

properties intermediate between metals and nonmetals.

Question 35

The properties of metals are...

Answer 35

Solid at room temperature, highly malleable, conductive. Form CATIONS.

Question 36

The properties of nonmetals are...

Answer 36

Solid or gas at room temperature, brittle, nonconductive. Form ANIONS.

Question 37

Elements on the periodic table are arranged according to...

Answer 37

Atomic number.

Question 38

The Octet Rule

Answer 38

Elements usually react in such a ay to attain the electron of the closest noble gas; elements on the right side of the table move "forward", and elements on the right side of the table move "backwards." Based on PERIOD.

Question 39

The Octet Rule is very helpful when...

Answer 39

Predicting the charges of ions.

Question 40

A mole contains...particles.

Answer 40

6.022 x 10^23