Unit II

Question 1

Substance

Answer 1

A form of matter that has a uniform, and unchanging composition; also known as a pure substance

Question 2

Mixture

Answer 2

A physical blend of two or more substances and any proportion, in which each substance retains its individual properties; can be separated by physical means

Question 3

Element

Answer 3

Pure substance that cannot be broken down into simpler substances by physical or chemical means

Question 4

Compound

Answer 4

A chemical combination of two or more elements; can be broken down into simpler substances by chemical means as properties different from those of its component elements

Question 5

Metal

Answer 5

An element that is solid at room temperature, a good conductor of heat and electricity and is generally shiny, most metals are ductile and malleable

Question 6

Nonmetal

Answer 6

Elements that are generally gases or dull brittle solids that are poor conductors of heat and electricity

Question 7

Metalloid

Answer 7

Elements such as silicon or germanium, that have physical properties of both metals and nonmetals

Question 8

Physical property

Answer 8

A characteristic of matter that can be observed or measured without changing the samples composition, for example - density, color, taste, hardness, or melting point

Question 9

Chemical property

Answer 9

The ability or inability of a substance to combine with or change into one or more new substances

Question 10

Physical change

Answer 10

A type of change that alters the physical properties of a substance but does not change its composition

Question 11

Chemical change

Answer 11

A process involving one or more substances changing into new substances; also called a chemical reaction

Question 12

Precipitate

Answer 12

A solid produced in a chemical reaction in a solution

Question 13

Energy

Answer 13

The capacity to do work or produce heat; exist as potential energy which is stored in an object based on its position or composition, and kinetic energy, which is the energy of motion

Question 14

Matter

Answer 14

Anything that has mass and takes up space

Question 15

Thermochemistry

Answer 15

The study of heat changes that accompany chemical reactions in phase changes

Question 16

Exothermic

Answer 16

A chemical reaction in which more energy is released than is required to break bonds in the initial reaction

Question 17

Endothermic

Answer 17

A chemical reaction in which a greater amount of energy is required to break existing bonds in the reactants than is released when new bonds form in the product molecules

Question 18

Solid

Answer 18

A form of matter that has its own definite shape and volume, is incompressible and only expands slightly when heated

Question 19

Liquid

Answer 19

A form of matter that flows, has constant volume and takes the shape of its container

Question 20

Gas

Answer 20

A form of matter that flows to conform to the shape of its container and fill the containers entire volume and is easily compressed