Chemistry Mid-Term Exam

Chemistry

the study of the characteristics and structure of matter

Mass

a measure of the amount of matter in an object

Weight

the measure of the gravitational pull on an object

Percision

how close a set of measurements are to one another

Accuracy

how close a measurement is to the true value

Temperature

the measurement of the average amount of kinetic energy in an object.

Micrometer

what um stands for in the SI system

Matter

any substance that has mass and occupies space

Qualitative

a statement that describes an object or phenomenon without using numbers

water

common substance with density of 1g/m

quantitative

a statement that describes an object or phenomenon without using numbers

model

a mental or physical representation developed to deal with abstract ideas

mole

the Si base unit for the amount of substance

kilogram

the SI base unit for mass, KG

candela

the SI base unit for luminous intensity

kelvin

SI base unit for temperature, the temperature scale where absolute zero is assigned the numerical value of 0

millimeter

what mm stands for

mega

1,000,000

nano

10 to the -9

kilo

1000

technology

the practical use of science

independent variable

the variable the scientist controls

seconds

seconds

extensive property

physical property dependent on amount

physical property

observed or measure without changing identity

intensive property

physical property independent of amount

chemical property

ability of substance to change or combine

atomic number

number of protons in an atom

compound

made of two or more types of atoms chemically combined

homogenous solution

mixture with a uniform composition

heterogenous solution

mixture without a uniform composition

atom

smallest unit of an element

law of multiple proportions

the ratios in compounds with the same elements are always in whole number ratios

element

made of one type of atom

atomic mass

mass of protons and neutrons

isotopes

atoms with the same number of protons, different numbers of neutrons

law of definite proportions

specific compounds have their elements in the same ratio

period

horizontal collections of elements on the periodic table

group

vertical collections of elements on the periodic table

wave particle duality

every particle has both a wave and particle characteristic

photon

packet of EM energy

amplitude

height of wave from origin

quantum

smallest amount of energy gained or lost by an atom

frequency

number of waves per second

electromagnetic radiation

exhibits wave-like behavior, travels at the speed of light

atomic orbital

region of space occupied by an electron

excited state

has higher energy than ground state

quantum number

describes location of electron

Pauli exclusion principle

no two electrons can have the same four quantum numbers

energy sublevel quantum number

describes the shape of the orbital cloud

Heisenberg uncertainty principle

impossible to tell the location and velocity of electron

ground state

lowest energy state of an atom or electron

principal quantum number

describes the size of an electron cloud

valence electron

outer electrons

Lewis dot structure

diagram of outer electrons

John Newland

scientist that grouped elements in octaves

atomic number

properties of elements are periodic functions of their

Melendez

scientist who developed the first periodic table

octet rule

states that eight electrons in the outer level make an element unreactive

ionization energy

energy required to remove one electron from an isolated gaseous atom

electronegativity

measure of an atom to attract shared electrons to itself

ion

charged particle

cation

positive ion

ionic bond

electrostatic force that holds two oppositely charged particles together

formula unit

ratio of ions or compounds involved; coefficient

anion

negative ion

chemical bond

force that holds two atoms together

ionic compound

compounds that contain ionic bonds

crystal lattice

three dimensional arrangement of particles

lattice energy

energy required to seperate 1 mol of ions in a compound

electron sea model

proposes valence electrons in a metal are free to move around

monatomic ion

ion with one atom

polyatomic ion

ion with several atoms

oxidation number

charge on a monatomic atom

electrolyte

substance whose aqueous solution conducts electricity

delocalize electrons

electrons not bonded to 2 atoms

metallic bond

a bond between metals

alloy

mixture of 2 or more metals, ex brass

covalent bond

when electrons are shared

exothermic reaction

occurs when energy is released during a chemical reaction

endothermic

reaction that absorbs energy

double bond

bond has 2 shared electron pairs

double replacement

another term for metathesis reaction

combination

another term for synthesis reaction

reactant

every chemical formula to the left of the yield arrow in a chemical reaction

product

every chemical formula right of the yield arrow in a chemical reaction

base

a substance that releases hydroxide ions in a solution

acid

a substance that releases hydrogen ions in a solution

solute

the dissolved substances in a solution

solvent

the dissolving substance in a solution

Acid + Base Yields

Salt + Water

chemical reaction

the process by which one or more substances are rearranged to make a new substance

precipitate

a solid product produced by a reaction in a solution

spectator ions

ions that do no participate in a chemical reaction

→

yield arrow

(s)

solid

(cr)

crystalline solid

↑

gas

(l)

liquid

(g)

gas