Exam 1 Study Guide Flash Cards

Front 1

experiment

Back 1

Under specific conditions, nature is explored and observations are made according to a designed strategy.

Front 2

Hypothesis

Back 2

Based on results of experiment, a proposal for a scientific principle is suggested.
Following further experimentation, hypothesis can be rejected, modified, or accepted as a scientific principle

Front 3

theory

Back 3

is a model that explains the behavior of nature & provides a tested explanation of basic natural events.
It cannot be directly measured.

Front 4

natural law

Back 4

does not explain the behavior of nature but rather states a quantifiable relationship.
It can be directly measured.
Definition: Brief statement/mathematical equation concerning a fundamental relationship or natural regularity.

Front 5

Matter

Back 5

general term to describe anything that occupies space and can be perceived by the senses

Front 6

Mass

Back 6

the quantity of matter in a substance
Weight (W) – the measure of the heaviness of an object (W = m  g).

Front 7

Antoine Lavoisier

Back 7

proposed that the total mass remains constant during a chemical change/chemical reaction.
Mercury (Hg) + ½Oxygen (O2) Mercury (II) Oxide (HgO)

Front 8

Physical states of matter

Back 8

Solid, liquid, gas

Front 9

Physical Change

Back 9

a change in the form of matter, but not in its chemical identity.
Has a constant/definite composition
Examples: Allowing dry ice (CO2) to vaporize, dissolving salt (NaCl) in water

Front 10

Chemical Change

Back 10

1+ type(s) of matter is converted into a separate type(s) of matter.
Original materials cannot be separated by physical means.
Examples: Iron rusting (iron combining with oxygen to form iron oxides), gasoline combustion (converting to CO2 + H2O)

Front 11

Physical properties

Back 11

a characteristic that can be observed for a material without changing its physical identity.

Front 12

Chemical properties

Back 12

a characteristic of a material involving a chemical change

Front 13

Substance

Back 13

a type matter that cannot be separated into other kinds of matter by any physical means.
Substances can be classified as elements and compounds.

Front 14

Element

Back 14

substance that cannot be decomposed by any chemical means into a simpler substance.
114 known elements as listed on Periodic Table

Front 15

Compound

Back 15

– substance that is composed of 2+ elements chemically combined.
Examples: NaCl, H2O

Front 16

Joseph Louis Proust

Back 16

determined that a pure compound, from any origin, always contains a definite and constant proportion of the elements by mass. This is the Law of Definite Proportions (or Constant Composition).

Front 17

Mixture

Back 17

a material that can be separated by a physical means into 2+ substances.
Does not obey the law of definite proportions.

Front 18

Heterogeneous

Back 18

– mixture that consists of physically distinct parts, each with dissimilar properties.
Example: Mixture of sand & water, salt & sugar

Front 19

Homogeneous

Back 19

mixture that has uniform properties throughout the sample. (AKA solution!)
Example: Air, salt water