Chemistry: 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.

Question 2

matter

Answer 2

physical substance in general, as distinct from mind and spirit; (in physics) that which occupies space and possesses rest mass, especially as distinct from energy.

Question 3

Extensive Properties

Answer 3

Extensive properties, such as mass and volume, depend on the amount of matter being measured. Intensive properties, such as density and color, do not depend on the amount of the substance present. Physical properties can be measured without changing a substance’s chemical identity.

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

Question 5

Mass

Answer 5

a body of coherent matter, usually of indefinite shape and often of considerable size

Question 6

Volume

Answer 6

the amount of space that a substance or object occupies, or that is enclosed within a container, especially when great.

Question 7

Physical Property

Answer 7

Physical properties can be observed or measured without changing the composition of matter. Physical properties are used to observe and describe matter. Physical properties include: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity, and many others.

Question 8

Physical Change

Answer 8

Physical changes are changes affecting the form of a chemical substance, but not its chemical composition. Physical changes are used to separate mixtures into their component compounds, but can not usually be used to separate compounds into chemical elements or simpler compounds.

Question 9

Chemical Property

Answer 9

A chemical property is any of a material’s properties that becomes evident during, or after, a chemical reaction; that is, any quality that can be established only by changing a substance’s chemical identity. … They can also be useful to identify an unknown substance or to separate or purify it from other substances.

Question 10

Chemical Change

Answer 10

Chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. These processes are called chemical reactions and, in general, are not reversible except by further chemical reactions.

Question 11

Phase (Phase of Matter)

Answer 11

solid/liquid/plasma/gas

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). / liquid to solid

Question 16

Melting

Answer 16

Melting, or fusion, is a physical process that results in the phase transition of a substance from a solid to a liquid.

Question 17

Vaporization

Answer 17

liquid to gas

Question 18

Condensation

Answer 18

water that collects as droplets on a cold surface when humid air is in contact with it./the conversion of a vapor or gas to a liquid.

Question 19

Sublimation

Answer 19

Sublimation is the phase transition of a substance directly from the solid to the gas phase without passing through the intermediate liquid phase. Sublimation is an endothermic process that occurs at temperatures and pressures below a substance’s triple point in its phase diagram.

Question 20

Deposition

Answer 20

the process of giving sworn evidence.

Question 21

Substance (Pure Substance)

Answer 21

Pure and impure chemical substances. A pure element or compound contains only one substance, with no other substances mixed in. Impure materials may be mixtures of elements, mixtures of compounds, or mixtures of elements and compounds.

Question 22

Element

Answer 22

each of more than one hundred substances that cannot be chemically interconverted or broken down into simpler substances and are primary constituents of matter. Each element is distinguished by its atomic number, i.e., the number of protons in the nuclei of its atoms.

Question 23

Chemical Symbol

Answer 23

In relation to the chemical elements, a symbol is a code for a chemical element. … For example, “He” is the symbol for helium (New Latin name, not known in ancient Roman times), “Pb” for lead (plumbum in Latin), and “Hg” for mercury (hydrargyrum in Greek).

Question 24

Compound

Answer 24

a thing that is composed of two or more separate elements; a mixture.

Question 25

Mixture

Answer 25

a substance made by mixing other substances together.

Question 26

Homogeneous Mixture

Answer 26

A homogeneous mixture has the same uniform appearance and composition throughout. Many homogeneous mixtures are commonly referred to as solutions. A heterogeneous mixture consists of visibly different substances or phases. The three phases or states of matter are gas, liquid, and solid.

Question 27

Solution

Answer 27

a means of solving a problem or dealing with a difficult situation.

Question 28

Heterogeneous Mixture

Answer 28

A heterogeneous mixture is a mixture that composes of components that aren’t uniform or they have localized regions that all have different properties. Despite the term appearing to be highly scientific, there are various common substances that are heterogeneous mixtures.

Question 29

Filtration

Answer 29

the action or process of filtering something.

Question 30

Distillation

Answer 30

the action of purifying a liquid by a process of heating and cooling.

Question 31

Chemical Reaction

Answer 31

The substance (or substances) initially involved in a chemical reaction are called reactants or reagents. Chemical reactions are usually characterized by a chemical change, and they yield one or more products, which usually have properties different from the reactants.

Question 32

Reactant

Answer 32

a substance that takes part in and undergoes change during a reaction.

Question 33

Product

Answer 33

a quantity obtained by multiplying quantities together, or from an analogous algebraic operation.- end resuilt

Question 34

Precipitate

Answer 34

cause (a substance) to be deposited in solid form from a solution.

Question 35

Law of Conservation of Mass

Answer 35

The law of conservation of mass states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants.