Chem Test #1

Front 1

atoms

Back 1

subatomic particles that are the fundamental building blocks of ordinary matter

Front 2

molecules

Back 2

atoms bonded together in specific geometrical arrangements

Front 3

hypothesis

Back 3

tentative interpretation of explanation of observations

Front 4

scientific law

Back 4

brief statement that summarizes past observations and predicts future ones

Front 5

scientific theory

Back 5

a model for the way nature is and tries to explain what nature does and why

Front 6

pure substance

Back 6

made up of only one component and its composition is the same throughout

Front 7

mixture

Back 7

composed of two or more components in proportions that can vary from one sample to another

Front 8

compound

Back 8

a substance composed of two or more elements

Front 9

heterogeneous mixture

Back 9

composition varies from one region of the mixture to another (wet sand)

Front 10

homogeneous mixture

Back 10

same composition throughout (sweetened tea)

Front 11

decanting

Back 11

separating by slowly pouring off (water and sand)

Front 12

distillation

Back 12

slowly boiling off more volatile (easily evaporated) liquid

Front 13

units

Back 13

standard quantities used to specify measurements

Front 14

International System of Units (SI)

Back 14

based on the metric system

Front 15

SI base units:
Length, Mass, Time, Temp, Amount of substance, electric current, luminous intensity

Back 15

meter(m), kilogram(kg), second(s), kelvin(K), mole(mol), ampere(A), candela(cd)

Front 16

derived unit

Back 16

a combination of other units (m/s)

Front 17

intensive property

Back 17

one that is independent of the amount of a substance (density)

Front 18

extensive property

Back 18

one that depends on the amount of a substance (mass)

Front 19

significant figures

Back 19

non-place holding digits
0.0032=2 sig
0.00006=1 sig
45.000=5 sig
1200=ambiguous

Front 20

exact numbers

Back 20

have no uncertainty, therefore do not limit the number of sig figs in any calculation

Front 21

accuracy

Back 21

how close the measured value is to the actual value

Front 22

precision

Back 22

how close a series of measurements are to one another or how reproducible they are

Front 23

law of definite proportions

Back 23

all samples of a given compound, regardless of their source or how they were prepared, have the same proportions of their constituent elements

Front 24

law of multiple proportions

Back 24

when two elements (A and B) form two different compounds, the masses of element B combine with 1g of element A can be expressed as a ratio of small whole numbers

Front 25

electron

Back 25

negatively charged, low mass particle.

Front 26

radioactivity

Back 26

the emission of small energetic particles from the core of certain unstable atoms

Front 27

nuclear theory

Back 27

most of the atoms mass and all of its positive charge are contained in the nucleus
most of the volume of the atom is empty space, throughout which tiny electrons are dispersed.

Front 28

neutron

Back 28

similar in mass to a proton, neutral charge (hydrogen contains no neutron)

Front 29

atomic mass unit (amu)

Back 29

1/12 the mass of a carbon atom containing six protons and six neutrons, the mass of a proton or a neutron is approximately 1amu.

Front 30

atomic number

Back 30

given by the symbol, Z. Is the number of protons in the atoms nucleus.

Front 31

isotopes

Back 31

atoms with the same number of protons but differing numbers of neutrons.

Front 32

natural abundance

Back 32

the natural amount of an elements isotope.

Front 33

ion

Back 33

an atom that has gained or lost electrons, causing it to become a charged particle

Front 34

cation

Back 34

positively charged ion

Front 35

anion

Back 35

negatively charged ion. named ny adding "ide" to the end of the elements name

Front 36

metals

Back 36

lie in groups 1A,2A, 2-12, and to the left of the line. metals for cations. conductors of heat and electricity. malleable. ductile.

Front 37

non-metals

Back 37

C, N+, O++, F+++, group 8, H. appear in all three states, poor conductors. not ductile or malleable. solids are brittle.

Front 38

metalloids

Back 38

B, Si, Ge, As, Sb, Te, Po. B then right 1-down 1, zig zag to Po. Exhibit mixed properties, semiconductors.

Front 39

semiconductor

Back 39

highly temperature dependent, electrically conductive.

Front 40

transition metals

Back 40

rectangle in the middle. properties tend to be less predictable

Front 41

family

Back 41

horizontal rows

Front 42

groups

Back 42

vertical columns

Front 43

noble gases

Back 43

8A, mostly unreactive, very stable.

Front 44

alkali metals

Back 44

group 1A, reactive metals, =

Front 45

alkaline earth metals

Back 45

group 2A, fairly reactive metals, not quite as reactive as 1A

Front 46

halogens

Back 46

group 7A, very reactive nonmetals.

Front 47

atomic mass

Back 47

beneath each element on the periodic table. represents the average mass of the isotopes that compose that element , weighted according to the natural abundance of each isotope.

Front 48

mass spectrometry

Back 48

technique that separates particles according to their mass.

Front 49

mol

Back 49

6.022*10^23 atoms per mol (Avogadro's number)

Front 50

molar mass

Back 50

the mass if one mol of atoms of an element

Front 51

giga

Back 51

10^9

Front 52

mega

Back 52

10^6

Front 53

kilo

Back 53

10^3

Front 54

deci

Back 54

10^-1

Front 55

centi

Back 55

10^-2

Front 56

milli

Back 56

10^-3

Front 57

micro

Back 57

10^-6

Front 58

nano

Back 58

10^-9

Front 59

diatomic elemets

Back 59

O, H, N, F, Cl, I, Br