unit 2

Question 1

Chemistry

Answer 1

the branch of science that deals with the identification of the substances of which matter is composed; the investigation of their properties and the ways in which they interact, combine, and change; and the use of these processes to form new substances.
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Question 2

Matter

Answer 2

that which occupies space and possesses rest mass, especially as distinct from energy.

Question 3

Extensive Properties

Answer 3

Mass and volume are extensive properties, but hardness is intensive.

Question 4

Intensive Properties

Answer 4

An intensive property is a bulk property, meaning that it is a physical property of a system that does not depend on the system size or the amount of material in the system.

Question 5

Mass

Answer 5

Mass is a measure of the amount of matter in an object.

Question 6

Volume

Answer 6

Volume is the quantity of three-dimensional space occupied by a liquid, solid, or gas. Common units used to express volume include liters, cubic meters, gallons, milliliters, teaspoons and ounces.

Question 7

Physical Property

Answer 7

A physical property is any property that is measurable, whose value describes a state of a physical system.

Question 8

Physical Change

Answer 8

A physical property is any property that is measurable, whose value describes a state of a physical system.

Question 9

Chemical Property

Answer 9

a property or characteristic of a substance that is observed during a reaction in which the chemical composition or identity of the substance is changed

Question 10

Chemical Change

Answer 10

a change in their chemical properties or composition, resulting in the formation of at least one new substance: The formation of rust on iron is a chemical change.

Question 11

Phase (Phase of Matter)

Answer 11

The states in which matter can exist: as a solid, liquid, or gas. When temperature changes, matter can undergo a phase change, shifting from one form to another.

Question 12

Solid

Answer 12

firm and stable in shape; not liquid or fluid.

Question 13

Liquid

Answer 13

a substance that flows freely but is of constant volume, having a consistency like that of water or oil.

Question 14

gas

Answer 14

an airlike fluid substance which expands freely to fill any space available, irrespective of its quantity.

Question 15

Freezing

Answer 15

below 32°F (0°C).

Question 16

Melting

Answer 16

make or become liquefied by heat.

Question 17

Vaporization

Answer 17

Vaporization (or vapourisation) of an element or compound is a phase transition from the liquid phase to vapor.

Question 18

Condensation

Answer 18

water that collects as droplets on a cold surface when humid air is in contact with it.

Question 19

Sublimation

Answer 19

When anything solid turns into a gas without first becoming liquid, that’s sublimation.

Question 20

Deposition

Answer 20

Deposition is a process where a gas changes phase and turns directly in solid without passing through the liquid phase.

Question 21

Substance (Pure Substance)

Answer 21

Pure substances are defined as substances that are made of only one type of atom or molecule.

Question 22

Element

Answer 22

An element is composed of atoms that have the same atomic number, that is, each atom has the same number of protons in its nucleus as all other atoms of that element.

Question 23

Chemical Symbol

Answer 23

an abbreviation or short representation of a chemical element; the symbols in the periodic table.

Question 24

Compound

Answer 24

A compound is a substance formed when two or more chemical elements are chemically bonded together.

Question 25

Mixture

Answer 25

a substance made by mixing other substances together.

Question 26

Homogeneous Mixture

Answer 26

A homogeneous mixture is simply any mixture that is uniform in composition throughout.

Question 27

Solution

Answer 27

In chemistry, a solution is a homogeneous mixture composed of two or more substances.

Question 28

Heterogeneous Mixture

Answer 28

A mixture is a combination of two or more pure substances in which the original substances retain their chemical properties.

Question 29

Filtration

Answer 29

Filtration is any of various mechanical, physical or biological operations that separate solids from fluids (liquids or gases) by adding a medium through which only the fluid can pass.

Question 30

Distillation

Answer 30

Distillation can be used to purify water or other substances, or to remove one component from a complex mixture, as when gasoline is distilled from crude oil or alcohol from a mash.

Question 31

Chemical Reaction

Answer 31

a process that involves rearrangement of the molecular or ionic structure of a substance, as opposed to a change in physical form or a nuclear reaction.

Question 32

Reactant

Answer 32

The substances that result from this recombination of atoms are called the products of the reaction.

Question 33

Product

Answer 33

Products are the species formed from chemical reactions. During a chemical reaction reactants are transformed into products after passing through a high energy transition state.

Question 34

Precipitate

Answer 34

cause (an event or situation, typically one that is bad or undesirable) to happen suddenly, unexpectedly, or prematurely.

Question 35

Law of Conservation of Mass

Answer 35

the principle that in any closed system subjected to no external forces, the mass is constant irrespective of its changes in form; the principle that matter cannot be created or destroyed.