Ch 3

Question 1

matter

Answer 1

anything that has volume and mass

Question 2

element

Answer 2

a substance that cannot be broken down into simpler substances

Question 3

nucleus

Answer 3

the center of an atom (made up of protons and neutrons)

Question 4

proton

Answer 4

tiny particle that has mass and a positive electric charge

Question 5

neutron

Answer 5

a particle with the same mass as a proton, but is neutral (has no electric charge)

Question 6

electron

Answer 6

has little mass, but has a negative charge

Question 7

atomic number

Answer 7

the number of protons in the atom’s nucleus

Question 8

mass number

Answer 8

the sum of the protons and neutrons in an atom’s nucleus

Question 9

isotopes

Answer 9

atoms of the same element that have the same number of protons, but a different number of neutrons so it they have different mass numbers

Question 10

ion

Answer 10

an atom that gains or loses an electron and has a net electric charge

Question 11

compound

Answer 11

a substance that is composed of atoms of two or more different elements that are chemically combined

Question 12

chemical bond

Answer 12

the force that holds together the elements in a compound

Question 13

covalent bond

Answer 13

an attraction of two atoms for a shared pair of electrons that holds the atoms together

Question 14

molecule

Answer 14

composed of two or more atoms held together by covalent bonds

Question 15

ionic bond

Answer 15

an attractive force between two ions of opposite charge

Question 16

metallic bond

Answer 16

a bond that allows metals to conduct electricity because the electrons can move freely

Question 17

chemical reaction

Answer 17

the change of one or more substances into other substances

Question 18

solution

Answer 18

a mixture in which the component particles cannot be distinguished from each other, even though they still retain their original properties

Question 19

acid

Answer 19

a solution containing a substance that produces hydrogen ions in water (H+)

Question 20

base

Answer 20

a substance that produces hydroxide ions in water (OH-)

Question 21

crystalline structures

Answer 21

a solid with densely packed particles arranged in regular geometric patterns

Question 22

glass

Answer 22

a solid that consists of densely packed atoms arranged randomly

Question 23

evaporation

Answer 23

the process of change from a liquid to a gas at temperatures below the boiling point

Question 24

plasmas

Answer 24

hot, highly ionized, electrically conducting gases

Question 25

condensation

Answer 25

the process of gas being cooled to the boiling point, becoming a liquid

Question 26

sublimation

Answer 26

the slow change of state from a solid (ice crystals) to a gas (water vapor) without an intermediate liquid state