Chemistry Exam 1 Things to Memorize

A pure substance that can't be broken down into simpler unique substances by ordinary chemical means

Element

A particle composed of two of more atoms, in which the atoms are chemically combined by sharing electrons

Molecule

Nitrogen is a gas at room temperature, with a density of 1.024 g/L. These are examples of ____ properties

Physical

A _____ mixture has a composition that varies within a particular sample of the mixture

Heterogeneous

Properties that depend upon the sample size of a substance are called _____ properties

Extensive

The ____ _____ of an object depends upon its position in a field.

Potential Energy

A ____ is an attraction or repulsion affecting matter.

Force

____ changes to a substance result in the production of a new substance

Chemical

The SI unit for temperature is the ____.

kelvin (K)

Protons and neutrons are called ____, due to their location in an atom.

Nucleons

The ____ Number specifies the number of protons and neutrons in a specific atom of an element.

Mass (A)

A/An ____ is a fundamental particle with the mass of an electron, but with a positive charge.

Positron (β+)

A law is a summary of a pattern of behavior or phenomena, with no explanation of that
behavior or phenomenon offered

A Law

How a law differs from a theory

Theories explain, laws declare cause-and-effect. Both can be
used for predicting unobserved behavior or phenomena

A theory is a tested, generally-accepted explanation for
behavior or phenomena

A Theory

A stable combination of two or more atoms, in which the atoms are chemically combined

Molecule

A pure substance composed of two or more atoms of different elements

Compound

Distinguish between Molecule and Compound

A molecule is a particle, a tiny piece of matter. A compound is substance, a specific
type of matter. The smallest particle of some compounds (but not all!) is a molecule, and
there are molecules of the other type of matter, elements. The two terms are NOT
interchangeable.

Matter that consists of two or more substances in variable amounts
(ex: salt and table sugar)

Mixture

Distinguish between Compound and Mixture

A compound is a pure substance composed of two or more elements, with a fixed or
constant ratio (by mass and by number of atoms), in which the atoms are chemically
combined (bonded). A mixture is composed of two or more different substances (elements
and/or compounds), with a variable composition: the ratio of substances can be changed.
Also, the forces holding the particles together in a mixture are rarely chemical bonds.

Compound: two or more atoms made of different elements
Mixture: two or more substances in variable amounts (ex: salt and table sugar)

Intensive properties are independent of the sample size; they are properties intrinsic
to the substance. Examples are density, melting point, and temperature

Intensive Properties

Extensive
properties depend upon the amount of the substance in the sample. Examples include
mass, volume, and heat content

Extensive Properties

Distinguish between Intensive and Extensive Properties

Intensive properties don't change based on the amount of substance- smaller amount to bigger amount is still ≈ to smaller mass to bigger mass and volume.
Extensive properties do change based on the amount of substance, a smaller amount of stuff=smaller mass and affects the amount (density) of the substance.

Round 0.2001576 cm to 4 significant figures

0.2002 cm

Round 1.332099 mL to 4 significant figures

1.332mL

Write 0.000997355 kg in proper scientific notation to 3 sig. figs.

9.97×10^-4 kg

Write 273.155 K in proper scientific notation to 3 sig. figs.

2.73 × 10² K

pico-(p)

one-trillionth (10 ‾¹²)

nano-(n)

one-billionth (10^ -9)

micro-(µ)

one-millionth (10^-6)

milli-(m)

one-thousandth (.001 or 10‾³)

centi-(c)

one-hundredth (.01 or 10‾²)

deci-(d)

one-tenth (.1 or 10‾¹)

kilo-(k)

one thousand (1,000 or 10³)

mega-(M)

one million (10^6)

giga-(G)

one billion (10^9)

Temperature Conversion °F ⇒ °C

°F=32+ 9/5×° C

Temperature Conversion °C ⇒ °F

°C=5/9×(°F−32)

Temperature Conversion K ⇒ °C

K=°C+273.15

carbon
symbol & atomic number

C
Atomic number: 6

fluorine
symbol & atomic number

F
Atomic number: 9

gold
symbol & atomic number

Au
Atomic number: 79

iodine
symbol & atomic number

I
Atomic number: 53

phosphorus
symbol & atomic number

P
Atomic number: 15

helium
symbol & atomic number

He
Atomic number: 2

tin
symbol & atomic number

Sn
Atomic number: 50

oxygen
symbol & atomic number

O
Atomic number: 8

iron
symbol & atomic number

Fe
Atomic number: 26

hydrogen
symbol & atomic number

H
Atomic number: 1

lead
symbol & atomic number

Pb
Atomic number: 82

nitrogen
symbol & atomic number

N
Atomic number: 7

sodium
symbol & atomic number

Na
Atomic number: 11

magnesium
symbol & atomic number

Mg
Atomic number: 12

aluminum
symbol & atomic number

Al
Atomic number: 13

silicon
symbol & atomic number

Si
Atomic number: 14

sulfur
symbol & atomic number

S
Atomic number: 16

chlorine
symbol & atomic number

Cl
Atomic number: 17

potassium
symbol & atomic number

K
Atomic number: 19

calcium
symbol & atomic number

Ca
Atomic number: 20

bromine
symbol & atomic number

Br
Atomic number: 35

silver
symbol & atomic number

Ag
Atomic number: 47

mercury
symbol & atomic number

Hg
Atomic number: 80

Radioactivity

Radioactivity is a property of certain unstable nuclei, in which the unstable nucleus
spontaneously disintegrates, giving off radiation in the form of particles, energy or both

Ionization

The formation of ions

Cations

Positive ions, formed by loss of electrons

Anions

Negative ions, formed by gain of electrons

Radioactive Decay

The process in which a nucleus spontaneously disintegrates, giving off (nuclear) radiation

Radiation

Energy that flows from a source
ex: energy, heat, light

John Dalton's explanation of Lavoisier's "Law of Conservation of Mass"
(Law of Conservation of Matter)

The Law of Conservation of Mass states that in any process mass is conserved: the mass of
the products (the final mass) equals the mass of the reactants (the initial mass). Dalton explained this relationship by postulating that atoms, the fundamental particles making up
all matter, can neither be created nor destroyed, nor could atoms of one element be
transformed into atoms of another element. Dalton also stated that chemical reactions
simply involved a reorganization of atoms. Together these statements explain Lavoisier’s
law.

When a chemical reaction takes place, matter is neither created nor destroyed.

Intensive vs. Extensive Properties

Intensive properties do not depend
upon the size of the sample
measured
Extensive properties do depend upon
the amount of stuff

The difference between the terms Atomic Mass and Mass Number

The mass number is a number of particles: the total number of protons and neutrons
(together, the nucleons) in the nucleus of a specific isotope. The atomic mass of an atom is
the actual mass of (amount of matter in) an atom, which takes into account the mass of the
nucleons, the electrons, and the mass defect due to the binding energy. The average atomic
mass found on the periodic table is an average of the masses of all the known isotopes of
an element, the average being “weighted” by the relative abundance of those isotopes in
nature. The mass of each isotope is determined by comparing it to the mass of a carbon-12
atom, which mass is defined to be exactly 12 atomic mass units (amu).