Chemistry Vocab Ch 1

Front 1

experiment

Back 1

an observation of natural phenomena carried out in a controlled manner so that the results can be duplicated and rational conclusions obtained

Front 2

law

Back 2

concise statement of mathematical equation about a fundamental relationship or regularity of nature

Front 3

hypothesis

Back 3

tentative explanation of some regularity of nature

Front 4

theory

Back 4

tested explanation of basic natural phenomena

Front 5

mass

Back 5

quantity of matter in a material

Front 6

matter

Back 6

whatever occupies space and can be perceived by our senses

Front 7

law of conservation of mass

Back 7

total mass remains constant during a chemical change (chemical reaction)

Front 8

physical change

Back 8

a change in the form of matter but not in its chemical identity

Front 9

chemical change (chemical reaction)

Back 9

change in which one of more kinds of matter are transformed into a new kind of matter or several new kinds of matter

Front 10

physical property

Back 10

characteristic that can be observed for a material without changing ints chemical identity (ex. melting point and color)

Front 11

chemical property

Back 11

characteristic of a material involving its chemical change (chemical property of iron is its ability to react with oxygen to produce rust)

Front 12

substance

Back 12

kind f matter that cannot be separated into other kinds of matter by any physical process

Front 13

element

Back 13

a substance that cannot be decomposed by any chemical reaction into similar substances

Front 14

compound

Back 14

substance composed of two or more elements chemically combined

Front 15

compound

Back 15

substance composed of two or more elements chemically combined

Front 16

law of definite proportions (law of constant composition)

Back 16

a pure compound, whatever its source, always contains definite or constant proportions of the elements by mass

Front 17

mixture

Back 17

material that can be separated by physical means into two or more substances

Front 18

heterogeneous mixture

Back 18

mixture that consists of physically distinct parts each with different properties

Front 19

homogeneous mixture (solution)

Back 19

mixture that is uniform in its properties throughout given samples

Front 20

phase

Back 20

one of several different homogeneous materials present in the portion of matter under study

Front 21

precision

Back 21

closeness of the set of values obtained from identical measurememts of a quantity

Front 22

accuracy

Back 22

closeness of a single measurement to its true value

Front 23

exact number

Back 23

number that arises when you count items or sometimes when you define a unit (12 inches in a foot)

Front 24

kilogram (kg)

Back 24

2.2 pounds

Front 25

Celsius (c)

Back 25

C= 1.8 * (F-32)

Front 26

Kelvin

Back 26

K= C +273

Front 27

Density

Back 27

D=m/v

Front 28

dimensional analysis (factor-label method)

Back 28

method of calculation in which one carries along the units for quantities