Chapter 1 Vocabulary

Question 1

Pure Substance

Answer 1

same chemical and physical properties throughout; cannot be separated into simpler substances by a physical process

Can be an element or a compound

Question 2

What is a physical process?

Answer 2

a transformation of a sample of matter that does not alter the chemical identity

Question 3

Element

Answer 3

a pure substance that cannot be separated into simpler substances by any chemical process

Question 4

Compound

Answer 4

a pure substance composed of two or more elements bonded together in fixed proportions; can be broken down into individual elements by chemical reactions

Question 5

Mixture

Answer 5

combination of two or more substances; can be homogenous or heterogeneous

Question 6

homogenous mixture

Answer 6

components are distributed uniformly throughout the sample and have no visible boundaries or regions

Question 7

heterogenous mixture

Answer 7

the components are not distributed uniformly and may have distinct regions of different composition

Question 8

Atom

Answer 8

smallest particle of an element that retains the chemical characteristics of that element

Question 9

Molecule

Answer 9

assembly of two or more atoms that are held together in a characteristic pattern by chemical bonds

Question 10

Chemical formula

Answer 10

notation for representing elements and compounds; consists of symbols of elements and subscripts identifying the number of atoms of each element in one molecule

Question 11

Chemical reaction

Answer 11

the transformation of one or more substances into different substances

Question 12

Chemical equations

Answer 12

Use chemical formulas to express
the identities of substances involved
in a reaction; Use coefficients to indicate
quantities of substances involved in
a reaction.

Question 13

Law of Constant Composition

Answer 13

All samples of a particular compound contain the same elements combined in the same proportions.

Example:
* Water (H2O)
* Consists of two units of hydrogen (H) combined with one unit of oxygen (O)
* Elements and proportions are represented by chemical formulas.

Question 14

Ions

Answer 14

compounds consisting of positively or negatively charged particles

Can be Cations: positively charged ions
Ex: Calcium ion is Ca^2+

Can be Anions: negatively charged ions
Ex: Hydroxide ion is OH^-

Question 15

Ways to represent bonding and shape for an arrangement of atoms

Answer 15

structural formulas, ball-and-stick model, and space-filling model

Question 16

Properties of Matter

Answer 16

Intensive property and extensive property

Question 17

Intensive property

Answer 17

A property that is independent of the amount of substance present

Examples – color, luster, melting and boiling points, hardness, and density

Question 18

Extensive Property

Answer 18

A property that varies with the quantity of the substance present

Examples: volume, mass

Question 19

Physical Property

Answer 19

A property of a substance that can be observed without changing it into another substance

Examples: luster, hardness, color, state, melting point, boiling point, density

Question 20

Chemical Property

Answer 20

A property of a substance that can be observed only by reacting it to form another substance

Examples: flammability

Question 21

Density

Answer 21

Ratio of the mass of an object/substance to the volume of the object/substance

Density = mass/volume

Question 22

States of matter

Answer 22

Solids: Definite shape and volume

Liquids: Occupies definite volume, but flows to assume the shape of its container

Gases (vapors): Neither definite shape nor volume; expands to fill its container

When there is a transformation from one
state to another due to addition or removal
of heat, a state change occurs.

Question 23

Hypothesis

Answer 23

A tentative and testable explanation for an observation or a series of observations

Question 24

Scientific Theory

Answer 24

A general explanation of widely observed phenomena that has been extensively tested and validated

Question 25

Scientific Method

Answer 25

• observe natural phenomena
• generate predictions to test hypothesis
• test the hypothesis
• analyze the results: could lead back to refining the experiment, modifying the hypothesis, or rejecting the hypothesis
• establish a theory(or model): could continue to test in light of the additional observation

Question 26

Accuracy

Answer 26

agreement between a measured value and accepted value

Question 27

Precision

Answer 27

agreement between repeated measurements

Question 28

Name the temperature scales and the temperature conversions

Answer 28

Fahrenheit, Celsius, and Kelvin

K = C + 273.15
C = 5/9 (F - 32)
F = 9/5C + 32