Chemistry The Easy Way - Chapter 1

Front 1

accuracy

Back 1

How close a measurement is to its known or accepted value.

Front 2

activation energy

Back 2

The energy necessary to get the reaction going by increasing the energy of the reactants so that they can combine.

Front 3

Celsius

Back 3

Based on the concept of diving the distance on a thermometer between the freezing point & boiling point of water and dividing into 100 equal degrees.

C=5/9(F-32)

C=K-273

Front 4

chemical change

Back 4

Changes in the composition and structure of a substance. Always accompanied by energy changes.

Front 5

chemical property

Back 5

Can be observed in regard to whether or not a substance reacts with other substances (i.e. iron rusts in moist air)

Front 6

compound

Back 6

Two or more kinds of atoms joined together in definite grouping.

Front 7

density

Back 7

The mass per unit volume of a substance.

D=m/V

Front 8

element

Back 8

Substance made up of only one kind of atom.

Front 9

endothermic

Back 9

In a chemical change, the structure needs to absorb more energy than is available from the reactants.

Front 10

exothermic

Back 10

In a chemical change, the energy released in the formation of a new structure exceeds the chemical energy of the original substances, and energy is given off, usually in the form of heat or light or both.

Front 11

Fahrenheit

Back 11

F=9/5C+32

Front 12

gas

Back 12

State of matter that has neither a definite shape nor a definite volume.

Front 13

heterogeneous

Back 13

A mixture in which the composition is indefinite (i.e. granite, wood, blood).

Front 14

homogeneous

Back 14

A mixture in which the composition is definite (i.e. air, sugar in water, stainless steel).

Front 15

inertia

Back 15

The property of matter whereby it remains at rest, or, if in motion, remains in motion in a straight line unless acted on by an outside force.

Property of mass to resist a change of position or motion.

Front 16

Kelvin

Back 16

Scale based on the lowest theoretical temperature (absolute zero -273 C)

K=C+273

C=K-273

Front 17

kilocalorie (kcal)

Back 17

Equal to 1000 cal.

Quantity of heat that will increase the temperature of 1 kg of water by 1 degree on the Celsius scale.

1 cal is approximately 4.18J

Front 18

kinetic energy

Back 18

Energy in motion.

Front 19

liquid

Back 19

State of matter that has a definite volume but takes the shape of the container.

Front 20

mass

Back 20

The quantity of matter that a substance possesses.

Depending on the gravitational force acting on it, it has a unit of weight assigned to it.

Front 21

matter

Back 21

Anything that occupies space and has mass.

Front 22

meniscus

Back 22

The "skin" of a liquid at which a volume measurement is read.

Front 23

mixture

Back 23

1) Composition is indefinite and usually heterogeneous.

2) Properties of the constituents are retained.

3) Parts of the mixture react differently to changed conditions.

Front 24

physical change

Back 24

Alters the physical properties of matter, but the composition remains constant.

Most often altered properties are form and state.

Front 25

physical property

Back 25

Those properties that can usually be observed with our senses.

Front 26

potential energy

Back 26

Energy due to position.

Front 27

precision

Back 27

Indicates the reliability or reproducibility of a measurement.

Front 28

scientific notation

Back 28

A system that uses the exponential means of expressing figures.

Front 29

significant figures

Back 29

All the digits that are certain plus one uncertain digit.

Front 30

SI units

Back 30

The most common system of measurement in the world.

A modernized metric system designated in 1960.

Has 7 basic units that can be used to express the fundamental properties of measurement.

Front 31

solid

Back 31

A state of matter that has both a definite size and shape.

Front 32

uncertainty

Back 32

Regardless of precision and accuracy, all measurements have a degree of uncertainty. Depended on two factors:

1) limitation of the measuring instrument.

2) Skill of the person making the measurement.

Front 33

weight

Back 33

The measure of the force with which a body is attracted toward the earth by gravity.

Front 34

Law of Conservation of Energy

Back 34

Energy is neither created nor destroyed in ordinary physical and chemical changes.

Front 35

Law of Conservation of Matter

Back 35

In a chemical change, matter can neither be created nor destroyed, but only changed from one form to another.

Front 36

Law of Conservation of Mass and Energy

Back 36

Mass and energy are interchangeable under certain conditions.

E=mc^2

Front 37

Law of Definite Composition or Proportion

Back 37

Compounds are made by combining elements in a definite proportion (or ratio) by mass and are made up of two or more kinds of atoms.