Midterm 1

Question 0

Matter

Answer 0

The physical material of the universe. Anything that has mass and occupies space.

Question 1

Chemistry

Answer 1

The study of matter and the changes that matter undergoes.

Question 2

Property

Answer 2

Any characteristic that allows us to recognize a particular type of matter and to distinguish it from other types.

Question 3

Elements

Answer 3

100 substances that when combined create a tremendous variety of matter on Earth.

Question 4

Atoms

Answer 4

The almost infinitesimally small building blocks of matter.

Question 5

Molecules

Answer 5

Two or more atoms are joined together in specific shapes.

Question 6

States of Matter

Answer 6

The forms that a sample of matter can be in (gas, liquid, solid) some of their observable properties.

Question 7

Gas

Answer 7

Has no fixed volume or shape; conforms to shape of its container.

Question 8

Liquid

Answer 8

Distinct volume that is independent of its container, but has no specific shape.

Question 9

Solid

Answer 9

Has definite shape and volume

Question 10

Pure Substance

Answer 10

Matter that has distinct properties and a composition that does not vary from sample to sample.

Question 11

Elements

Answer 11

Substances that cannot be decomposed into similar substances.

Question 12

Compounds

Answer 12

Substances composed of two or more elements.

Question 13

Mixtures

Answer 13

Combinations of two or more substances in which each substance retains its chemical identity.

Question 14

Law of Constant Composition (Law of Definite Proportions)

Answer 14

The observation that the elemental composition of a compound is always the same. Law stated in 1800s by Joseph Louis Proust.

Question 15

Solutions

Answer 15

Homogenous mixtures (uniform thought substance). Can be solid, liquid or gas.

Question 16

Physical Properties

Answer 16

Properties that can be observed without changing the identity and the composition of the substance.

Color, odor, density, melting point, boiling point and hardness (malleability).

Question 17

Chemical Properies

Answer 17

Properties that describe the way a substance may change, or react, to form other substances.

Flammability

Question 18

Intensive Properties

Answer 18

Properties that do not depend on the amount of sample being examined. Can be used to identify substances.

Temperature, Melting Point

Question 19

Extensive Properties

Answer 19

Properties that depend on the amount that is being sampled.

Volume and Mass.

Question 20

Physical Change

Answer 20

When a substance changes its physical appearance but not its composition.

Evaporation of water

Changes of state

Question 21

Chemical Change (Chemical Reaction)

Answer 21

When a substance is transformed into a chemically different substance.

Hydrogen burning in the air, Combines with oxygen to form water.

Question 22

Metric system

Answer 22

Units used for scientific measurements

Question 23

Distillation

Answer 23

A process that depends on the different abilities of substances to form gases.

An important method of separating the components of a homogeneous mixture.

Question 24

Scientific law

Answer 24

A concise verbal statement or mathematical equation that summarizes a broad variety of observations and experiences. They describe the behavior of matter.

Question 25

S I units

Answer 25

International French system of units

Question 26

Mass

Answer 26

Kilogram KG

Question 27

Length

Answer 27

Meter M

Question 28

Time

Answer 28

Second SEC

Question 29

Temperature

Answer 29

Kelvin K

Question 30

Amount of substance

Answer 30

Mole mol

Question 31

Electric current

Answer 31

Ampere A amp

Question 32

Luminous intensity

Answer 32

Candela cd

Question 33

Mass

Answer 33

A measure of the amount of material in an object.

Question 34

Absolute zero

Answer 34

Zero on Kelvin scale Lowest attainable temperature -273.15°C

Question 35

Density

Answer 35

The amount of mass in a unit volume of a substance Density equals mass over volume.

Question 36

Precision

Answer 36

A measure of how closely individual measurements agree with one another.

Question 37

Accuracy

Answer 37

Refers to how closely individual measurements agree with the correct or "true" value.

Question 38

Significant figures

Answer 38

All digits of a measured quantity including the uncertain one.

Question 39

Conversion factor

Answer 39

Fraction whose numerator and denominator are the same quantity expressed in different units.

Question 40

Átomos

Answer 40

Indivisible or uncuttable

Question 41

Law of constant composition

Answer 41

In a given compound the relative numbers and kinds of atoms are constant.

Question 42

The law of conservation of mass

Answer 42

The total mass of materials present after a chemical reaction is the same as the total mass present before the reaction.

Question 43

The Law of multiple proportions

Answer 43

If two elements A and B combined to form more than one compound the masses of B that can combine with a given mass of A are in the ratio of small whole numbers.

Question 44

Dalton's atomic theory

Answer 44

1. Each element is composed of extremely small particles called atoms 2. All atoms of a given element are identical but the atoms of one element are different from the atoms of all other elements. 3. Atoms of one element cannot be changed into atoms of different elements by chemical reactions; atoms are neither created or destroyed in chemical reactions. 4. Compounds are formed when atoms of more than one element combined a given compound always has the same relative number and kind of atoms.

Question 45

Cathode rays

Answer 45

The radiation that was produced between the electrodes when a high-voltage was applied to the electrodes in the tube.