6.1-6.3 Test

Question 1

atom

Answer 1

building block of matter; contains subatomic particles-neutrons, protons, and electrons

Question 2

nucleus

Answer 2

center of an atom; contains neutrons and protons

Question 3

proton

Answer 3

positively charged particle in an atom’s nucleus

Question 4

neutron

Answer 4

particle without a charge in an atom’s nucleus

Question 5

electron

Answer 5

negatively charged particle that occupies space around an atom’s nucleus

Question 6

element

Answer 6

pure substance composed of only one type of atom; cannot be broken down into another substance by physical or chemical means

Question 7

isotope

Answer 7

two or more atoms of the same element having different numbers of neutrons

Question 8

compound

Answer 8

pure substance with unique properties; formed when two or more different elements combine

Question 9

atomic number

Answer 9

the number of protons in an element

Question 10

atomic mass/mass number

Answer 10

protons+neutrons in an element

Question 11

radioactive isotopes

Answer 11

isotopes that give off radiation

Question 12

chemical bonds

Answer 12

the force that holds substances together

Question 13

ionic bonds

Answer 13

electrical attraction between two oppositely charged atoms or groups of atoms

Question 14

ions

Answer 14

atoms that are negatively or positively charged because it has lost or gained one or more electrons

Question 15

covalent bonds

Answer 15

type of chemical bond formed when atoms share electrons

Question 16

molecule

Answer 16

compound whose atoms are held together by covalent bonds

Question 17

chemical reaction

Answer 17

energy-requiring process by which atoms or groups of atoms in substances are changed into different substances

Question 18

reactant

Answer 18

substance that exists before a chemical reaction starts; located on the left side of the arrow in a chemical equation

Question 19

product

Answer 19

substance formed by a chemical reaction; located on the right side of the arrow in a chemical equation

Question 20

activation energy

Answer 20

minimum amount of energy needed for reactants to form products in a chemical reaction

Question 21

catalyst

Answer 21

substance that speeds up a chemical reaction by reducing the activation energy

Question 22

enzyme

Answer 22

protein that speeds up a biological reaction by lowering the activation energy needed to start the reaction

Question 23

substrate

Answer 23

reactant to which an enzyme binds

Question 24

active site

Answer 24

specific place where a substrate binds on an enzyme

Question 25

endothermic

Answer 25

reactions that absorb energy in the form of heat

Question 26

exothermic

Answer 26

reactions that release energy in the form of heat

Question 27

polar molecule

Answer 27

molecule with oppositely charged regions

Question 28

hydrogen bond

Answer 28

weak electrostatic bond formed by the attraction of opposite charges between a hydrogen atom and oxygen, fluorine, or nitrogen atom

Question 29

mixture

Answer 29

combination of two or more different substances in which each substance keeps it’s individual characteristics; can have a uniform composition(homogeneous) or have distinct area of substances(heterogeneous)

Question 30

solution

Answer 30

homogeneous moisture formed when a substance(the solute) is dissolved in another substance(the solvent)

Question 31

solvent

Answer 31

substance in which another substance is dissolved

Question 32

solute

Answer 32

substance dissolved in a solvent

Question 33

acid

Answer 33

substance that releases hydrogen ions(H+) when dissolved in water; an acidic solution has a pH less than 7

Question 34

base

Answer 34

substance that releases hydroxide ions(OH-) when dissolved in water; a basic solution has a pH greater than 7

Question 35

pH

Answer 35

measure of the concentration of hydrogen ions(H+) in a solution

Question 36

buffer

Answer 36

mixture that can react with an acid or a base to maintain the pH within a specific range

Question 37

homogeneous

Answer 37

when a mixture has a uniform composition throughout

Question 38

heterogeneous

Answer 38

when the components in a mixture remain distinct

Question 39

suspension

Answer 39

heterogeneous mixture where the particles settle out over time

Question 40

colloid

Answer 40

heterogenous mixture in which the particles do not settle out