[NOTES] Chapter 1: Keys to Studying Chemistry - Definitions, Units, and Problem Solving

Question 1

Chemistry

Answer 1

The scientific study of matter and its properties, the changes that matter undergoes, and the energy associated with those changes

Question 2

Matter

Answer 2

“stuff” of the universe, anything that has mass and volume

Question 3

Composition (of matter)

Answer 3

The types and amounts of simpler substances that make it up

Question 4

Substance

Answer 4

A type of matter that has a defined fixed composition

Question 5

Solid (state of matter)

Answer 5

Defined by a fixed shape that does not conform to the container shape

Question 6

Liquid (state of matter)

Answer 6

Defined by a varying shape that conforms to the container shape, but only to the extent of the liquid’s volume; that is, a liquid has an upper surface

Question 7

Gas (state of matter)

Answer 7

Defined by a varying shape that conforms tot he container shape, but it fills the entire container

Question 8

Properties (of matter)

Answer 8

The characteristics that give each substance its unique identity

Question 9

Physical Properties (of matter)

Answer 9

Characteristics a substance shows by itself, without changing into or interacting with another substance

Question 10

Physical Change

Answer 10

Occurs when a substance alters its physical properties, NOT its composition

Question 11

Chemical Properties (of matter)

Answer 11

Characteristics a substance shows as it changes into or interacts with another substance (or substances)

Question 12

Chemical Change/Chemical Reaction

Answer 12

Occurs with one or more substances are converted into one or more substances with difference composition and properties

Question 13

Energy

Answer 13

The abilities to do work, ex. moving something

Question 14

Potential Energy

Answer 14

The energy due to the position of the object relative to other objects

Question 15

Kinetic Energy

Answer 15

The energy due to the motion of the object

Question 16

Scientific Method

Answer 16

Not a step-by-step checklist, but rather a process involving creative proposals and tests aimed at objective, verifiable discoveries

Question 17

Observations

Answer 17

Facts our ideas explain, ex. quantitative observations are best because it reveals trends leading to quantitative information (data). In continuation, this leads to a natural law after being mathematically summarized

Question 18

Hypothesis

Answer 18

A proposal made to explain an observation, must be revised or discarded

Question 19

Experiment

Answer 19

A set of procedural steps that tests a hypothesis; often contains two variables (quantities that can have more than one value) and a control to remain constant

Question 20

Theory

Answer 20

Based on experiments that test hypothesis about observations distinguishing from scientific thinking from speculation

Question 21

Combustion

Answer 21

The process of burning a material in air

Question 22

SI Units

Answer 22

Based on 7 fundamental/base units, each identified with a physical quantity; all other units are derived

Question 23

Volume (V)

Answer 23

The amount of space matter occupies, usually uppercase for non-SI unites like the liter (L) and milliliter (mL)

Question 24

Conversion Factors

Answer 24

Ratios used to express a quantity in different units

Question 25

Density (d)

Answer 25

The mass of a sample of a substance divided by its volume (m/v ratio)

Question 26

Temperature (T)

Answer 26

A measure of how hot or cold one object is relative to another; use thermometer

Question 27

Heat

Answer 27

The energy that flows from an object with a higher temperature to an object with a lower temperature

Question 28

Extensive Properties

Answer 28

Are dependent on the amount of substance present; mass and volume

Question 29

Intensive Properties

Answer 29

Are independent of the amount of substance, ex. density

Question 30

Significant Figures

Answer 30

The digits we record, both the certain and the uncertain ones; unlike exact numbers that have no uncertainty associated with them

Question 31

Precision

Answer 31

Reproducibility, refers to how close the measurement is to the actual value

Question 32

Accuracy

Answer 32

Refers to how close each measurement is to the actual value

Question 33

Systematic Error

Answer 33

Produces values that are either all higher or all lower than the actual value - error is a part of the experimental system (faulty device or by a consistent mistake in taking a reading)

Question 34

Random Error

Answer 34

Produces values that are higher and lower than the actual value - size of error is dependent on the measurer's skill and the instrument's precision