Chapter 1

Question 1

Define Chemistry

Answer 1

The science that seeks to understand the behavior of matter by studying the behavior of atoms and molecules

Question 2

Basic steps of scientific method

Answer 2

Observation
Hypothesis
Experiment
Law/Theory

Question 3

Hypothesis

Answer 3

A tentative interpretation or explanation of the observations

Question 4

Experiment

Answer 4

Highly controlled procedures designed to generate observations that may confirm or refute a hypothesis

Question 5

Scientific law

Answer 5

WHAT;

A brief statement that summarizes past observations and predicts future ones

Question 6

Theory

Answer 6

WHY;
A model for the way nature is and tries to explain not merely what nature does but why; often predicting behavior far beyond the observations or laws from which they were developed.

Question 7

Matter

Answer 7

Anything that occupies space and mass
Pure Substances
Mixtures

Question 8

Solids

Answer 8

Atoms or molecules pack close to each other in fixed locations. Vibrate, but do not move around or past each other.
Fixed volume and rigid shape
Crystalline or amorphous

Question 9

Crystalline Solid

Answer 9

A solid where atoms or molecules are in patterns with long-range, repeating order. Geometric shape and arrangement of atoms (most times)
Eg. salt, diamonds

Question 10

Amorphous solid

Answer 10

A solid where atoms or molecules do not have any long-range order.

E.g glass and plastic. Possible intermediate between solids and liquids. Atoms are fixed in room temperature, but no long range structure and no distinct melting points

Question 11

Liquid matter

Answer 11

Atoms or molecules are tightly packed, but are free to move relative to each other.
Fixed volume
No fixed shape- Assume shape of container

Question 12

Gaseous matter

Answer 12

Atoms or molecules have lots of space between them and are free to move relative to one another, making gasses COMPRESSIBLE.
Assume shape AND volume of container
E.g. at room temp, helium, nitrogen, carbon dioxide.

Question 13

Element

Answer 13

A substance that cannot be chemically broken down into simpler substances

Question 14

Compound

Answer 14

A substance composed of two or more elements in a fixed definite proportion

Question 15

Pure substance

Answer 15

Made up of only one component and composition is invariant. Components can be individual atoms or groups of atoms joined together.
Elements and Compounds

Question 16

Mixture

Answer 16

Variable in composition
Two or more components in proportions that can vary from one sample to another.
Heterogeneous or homogeneous

Question 17

Homogeneous Mixture

Answer 17

Same composition throughout. Uniform composition because atoms or molecules that compose them mix uniformly.

Question 18

Heterogeneous Mixture

Answer 18

The composition varies from one region of the mixture to another. Made up of distinct regions because the atoms that compose them are separate.

Question 19

Physical property

Answer 19

A property that a substance displays without changing its composition
e.g. odor, taste, color, appearance, melting point, boiling point, and density

Question 20

Chemical Property

Answer 20

A property that a substance displays only by changing its composition via a chemical change.
e.g. flammability, corrosiveness, acidity, toxicity

Question 21

Physical Change

Answer 21

Changes that alter only state or appearance

Question 22

Chemical change

Answer 22

Changes that alter the composition of matter. Atoms rearrange, transforming the original substances into different substances.

Question 23

Energy

Answer 23

Capacity to do work. Work is the action of a force through a distance. Total energy is sum of its kinetic energy, potential energy, and thermal energy.

Question 24

Kinetic Energy

Answer 24

Energy associated with an objects motion

Question 25

Potential energy

Answer 25

Energy associated with its position or composition

Question 26

Thermal energy

Answer 26

Energy associated with the temperature of the object. A type of kinetic energy because it is associated with the motion of the individual atoms or molecules that make up the object.

Question 27

Measurements

Answer 27

Have units and has an error. Have significant figures.

Question 28

SI base units
Length
Mass
Time
Temperature
Amount of substance
Electric Current
Luminous intensity

Answer 28

Unit- Symbol
Meter (m)
Kilogram (kg)
Second (s)
Kelvin (K)
Mole (mol)
Ampere (A)
Candela (cd)

Question 29

Fahrenheit to Celcius

Answer 29

C=(F-32)/1.8

Question 30

Celsius to Kelvin

Answer 30

K= C+273.15

Question 31

Exact Numbers

Answer 31

Unlimited # of sig figs.
From the accurate counting of discrete objects

Defined quantities, such as the number of centimeters in 1 m. 100 cm = 1 m

From integral numbers that are part of an equation e.g. r=d/2, 2 is exact

Question 32

Significant figures

Answer 32

The preservatino of precision. The greater the number of sig figs, the greater the certainty of the measurement

Question 33

Accuracy

Answer 33

How close the measured value is to the actual value

Question 34

Precision

Answer 34

Refers to how close a series of measurements are to one another or how reproducible they are.

Question 35

Density

Answer 35

Mass/Volume
Volume- measure of space. Unit of length cubed (m^3). Liter or mL. 1 mL equal to 1 cm^3.

Intensive property: independent of the amount of substance (DENISTY)

Extensive Property - depends on amount of substance (mass)

Question 36

Water displacement

Answer 36

Object is placed in water and the change in volume of the water is measured. The increase in the total volume represents the volume of water displaced by the object and is equal to the volume of the object.