Chapter 1 Vocab (Brown-LeMay Chemistry The Central Science)

Question 1

Chemistry

Answer 1

The science that deals with the composition, structure, and properties of substances and with the transformations that they undergo

Question 2

Matter

Answer 2

material substance that occupies space, has mass, and is composed predominantly of atoms consisting of protons, neutrons, and electrons, that constitutes the observable universe

Question 3

Element

Answer 3

one of the basic substances that are made of atoms of only one kind and that cannot be separated by ordinary chemical means into simpler substances

Question 4

Atom

Answer 4

the smallest particle of a substance that can exist by itself or be combined with other atoms to form a molecule

Question 5

Property

Answer 5

a quality or trait belonging to a substance

Question 6

Molecule

Answer 6

The smallest particle of a substance that retains all the properties of the substance and is composed of one or more atoms

Question 7

Gas

Answer 7

A substance of very low density that has no definite shape or volume.

Question 8

Liquid

Answer 8

An amorphous (non-crystalline) form of matter between a gas and a solid that has a definite volume, but no definite shape.

Question 9

Solid

Answer 9

state of matter characterized by particles arranged such that their shape and volume are relatively stable

Question 10

Mixture

Answer 10

an association of substances, which cannot be represented by a chemical formula
•In a heterogeneous mixture the substances are not uniformly dispersed.
•”homogeneous mixture” is loosely used to describe two or more substances that are uniformly dispersed as in a solution of water and sodium chloride (salt water).

Question 11

Solution

Answer 11

a uniformly dispersed mixture of molecules or ions. The substance being dissolved is the solute, while the substance into which the solute is dissolved is the solvent.

Question 12

Pure substance

Answer 12

material that is composed of only one type of particle

Question 13

Compound

Answer 13

substance composed of atoms or ions of two or more elements that are chemically combined

Question 14

Law of constant composition
Or
Law of definite proportions

Answer 14

all samples of a given chemical compound have the same elemental composition by mass.

Question 15

Physical properties

Answer 15

Properties that do not change the chemical nature of matter. Examples of these are: color, smell, freezing point, boiling point, melting point, infra-red spectrum, attraction (paramagnetic) or repulsion (diamagnetic) to magnets, opacity, viscosity and density

Question 16

Chemical properties

Answer 16

A _______ is a characteristic or behavior of a substance that may be observed when it undergoes a chemical change or reaction.
Examples of these properties of a substance can include:toxicity, oxidation, flammability, heat of combustion, enthalpy of formation, chemical stability under specific conditions, and radioactivity

Question 17

Physical change

Answer 17

Any change that occurs without altering the chemical composition of a substance is a physical change. These can include changing the color, shape, state of matter, or volume of a substance.

Question 18

Chemical change

Answer 18

any change that results in the formation of new chemical substances
Iron rusting (iron oxide forms)
Gasoline burning(water vapor and carbon dioxide forms)

Question 19

Chemical reaction

Answer 19

process in which atoms of the same or different elements rearrange themselves to form a new substance

Question 20

Intensive property

Answer 20

do not depend on the amount of matter, such as density and color

Question 21

Extensive property

Answer 21

depend on the amount of matter that is being measured, such as mass and volume

Question 22

Scientific method

Answer 22

a method or procedure consisting of systematic observation, measurement, experimentation, and the formulation, testing, and modification of hypotheses

Question 23

Scientific law

Answer 23

statement based on repeated experimental observations that describes some aspects of the universe. Always applies under the same conditions, and implies that there is a causal relationship involving its elements.

Question 24

Hypothesis

Answer 24

Statement that can be supported or refuted through carefully crafted experimentation or observation.

Question 25

Theory

Answer 25

well-established explanation for scientific data

Question 26

Metric system

Answer 26

system of weights and measures based on the meter as a unit of length, the kilogram as a unit of mass, and the liter as a unit of volume.

Question 27

International System of Units(SI units)

Answer 27

the kilogram (kg), for mass
the second (s), for time
the kelvin (K), for temperature
the ampere (A), for electric current
the mole (mol), for the amount of a substance
the candela (cd), for luminous intensity
the meter (m), for distance

Question 28

Mass

Answer 28

• The quantity of matter contained in a particle or body regardless of its location in the universe and the gravitational force applied to it.
• Mass is constant, while weight is affected by the distance of the object from the center of the earth (or other such body).
• Mass is not affected by gravity. The mass of an object is responsible for its inertia (i.e. its resistance to being accelerated).

Question 29

Kelvin scale

Answer 29

the temperature scale used in chemistry, physics and some engineering calculations. Zero degrees Kelvin (-273 centigrade) is the temperature at which all thermal motion ceases

Question 30

Celsius scale

Answer 30

The scale for measuring temperature used internationally where the freezing point of water is zero and the boiling point of water at sea level is 100 degrees

Question 31

Density

Answer 31

The ratio of mass to unit volume expressed in grams/cm^3 for solids and liquids and grams/liter in gases (density=mass/volume).

Question 32

Precision

Answer 32

In measurement indicates a set of measurements that are very similar. They may or may not be close to the true answer.

Question 33

Accuracy

Answer 33

In measurement indicates that a set of measurements are close to the true answer, though they are not necessarily precise.

Question 34

Significant figure

Answer 34

any digit of a number that is known with certainty; any digit of a number beginning with the leftmost non-zero digit and ending with the rightmost non-zero digit

Question 35

Dimensional analysis

Answer 35

Dimensional Analysis is a way chemists and other scientists convert units of measurement. We can convert any unit to another unit of the same dimension. This means we can convert some number of seconds into another unit of time, such as minutes, because we know that there are always 60 seconds in one minute

Question 36

Conversion factor

Answer 36

a numerical ratio to express a measurement from one unit to another unit in the same dimension.
To change a time measurement from hours to days, a ______ of 1 day = 24 hours.

Question 37

Change of state

Answer 37

The physical process where matter moves from one state to another. Examples of such changes are melting, evaporation, boiling, condensation, freezing, crystallization, and sublimation.