Chapter 1: Keys to the Study of Chemistry

Question 1

calibration

Answer 1

The process of correcting for systematic error of a measuring device by comparing it to a known standard.

Question 2

Celsius scale

Answer 2

(formerly centigrade scale) A temperature scale in which the freezing and boiling points of water are defined as 0°C and 100°C, respectively.

Question 3

chemical change

Answer 3

(also chemical reaction) A change in which one or more substances are converted into one or more substances with different composition and properties.

Question 4

chemical property

Answer 4

A characteristic of a substance that appears as it interacts with, or transforms into, other substances.

Question 5

combustion

Answer 5

The process of burning in air, often with release of heat and light.

Question 6

composition

Answer 6

The types and amounts of simpler substances that make up a sample of matter.

Question 7

density

Answer 7

D=M/v

Question 8

dimensional analysis

Answer 8

(also factor-label method) A calculation method in which arithmetic steps are accompanied by canceling units that represent physical dimensions.

Question 9

energy

Answer 9

The ability to do work, that is, to move matter. [See also kinetic energy (Ek) and potential energy (Ep).]

Question 10

extensive property

Answer 10

A property, such as mass, that depends on the quantity of substance present.

Question 11

heat (q)

Answer 11

(also thermal energy) The energy transferred between objects because of a difference in their temperatures only.

Question 12

intensive property

Answer 12

A property, such as density, that does not depend on the quantity of substance present.

Question 13

Kelvin scale

Answer 13

(also absolute scale) The preferred temperature scale in scientific work, which has absolute zero (0 K, or − 273.15°C) as the lowest temperature.

Question 14

kelvin (K)

Answer 14

The SI base unit of temperature. The kelvin is the same size as the Celsius degree.

Question 15

mass

Answer 15

The quantity of matter an object contains. Balances are designed to measure mass.

Question 16

model

Answer 16

(also theory) A simplified conceptual picture based on experiment that explains how a natural phenomenon occurs.

Question 17

natural law

Answer 17

(also law) A summary, often in mathematical form, of a universal observation.

Question 18

random error

Answer 18

Error that occurs in all measurements (with its size depending on the measurer’s skill and the instrument’s precision) and results in values both higher and lower than the actual value.

Question 19

SI unit

Answer 19

A unit composed of one or more of the base units of the Système International d’Unités, a revised form of the metric system.

Question 20

systematic error

Answer 20

A type of error producing values that are all either higher or lower than the actual value, often caused by faulty equipment or a consistent flaw in technique.

Question 21

temperature (T)

Answer 21

A measure of how hot or cold a substance is relative to another substance. A measure of the average kinetic energy of the particles in a sample.

Question 22

uncertainty

Answer 22

A characteristic of every measurement that results from the inexactness of the measuring device and the need to estimate when taking a reading.

Question 23

variable

Answer 23

A quantity that can have more than a single value. (See also controlled experiment.)

Question 24

weight

Answer 24

The force that is exerted by a gravitational field on an object and is directly proportional to the object’s mass.