Biology Vocabulary Chemistry

Front 1

matter

Back 1

anything that has mass and takes up space

Front 2

element

Back 2

a substance that cannot be physically or chemically broken down into simpler substances with the same properties

Front 3

atom

Back 3

the smallest part of an element that displays all the properties of that element

Front 4

atomic symbol

Back 4

one or two letters that represent the name of an element

Front 5

nucleus

Back 5

the center of an atom that contains the protons and the neutrons of the atom

Front 6

electron shell

Back 6

the average location of electrons around an atom; also called an energy level

Front 7

proton

Back 7

positively charged subatomic particle located in the nucleus = 1 mass unit

Front 8

neutron

Back 8

subatomic particle located in the neutron with no charge - 1 mass unit

Front 9

electron

Back 9

negatively charged subatomic particle located outside the nucleus; does not affect the atoms atomic mass

Front 10

atomic number

Back 10

the unique identifying number of an element, equal to the number of protons in the atom

Front 11

atomic mass

Back 11

mass of an atom, the sum of the p and n

Front 12

isotope

Back 12

atoms of the same element but with different number of neutrons, thus different atomic masses

Front 13

tracer

Back 13

substance with an attache radioactive isotope that can be tracked in a biological system

Front 14

group

Back 14

vertical columns on the periodic table

Front 15

period

Back 15

horizontal columns on the periodic table

Front 16

valence electron

Back 16

electrons in the outermost energy orbits of electrons in the valence shell

Front 17

octet rule

Back 17

the outermost energy level of an atom desires a total of 8 electrons

Front 18

compound

Back 18

two ore more atoms bonded together

Front 19

molecule

Back 19

the smallest part of a compound that still has the same properties as the whole compound; created through covalent bonding

Front 20

ion

Back 20

a charged particle that results of the gain or loss of electrons in the atom

Front 21

ionic bond

Back 21

a bond occurring when two ions have transferred electrons with each other; electrons are not shared but given away

Front 22

covalent bond

Back 22

a bond that results from two atoms sharing one or more pairs of electrons; no atoms will lose electrons but temporarily borrow back and forth from each other to complete their octet

Front 23

nonpolar covalent bond

Back 23

a bond that results from two atoms sharing one or more pairs of electrons equally

Front 24

electronegativity

Back 24

the attraction within an atom for the electrons in its own valence shell or of those in a covalent bond

Front 25

polar covalent bond

Back 25

the uneven sharing of electrons in a covalent bond

Front 26

hydrogen bond

Back 26

a weak bond that arises between a slightly positive H atom in one molecule and a slightly negative atom in another or the same molecule

Front 27

calorie

Back 27

thae amount of energy needed to raise one gram of water one degree Celcius

Front 28

solvent

Back 28

substance that dissolves other substances

Front 29

solution

Back 29

fluid that contains dissolved substances

Front 30

solute

Back 30

substance that is dissolved into a solution by a solvent

Front 31

hydrophilic

Back 31

polar molecules or ions that attract water

Front 32

hydrophobic

Back 32

nonpolar molecules that repel water

Front 33

cohesive

Back 33

attractive property of molecules that are not easily separated from each other

Front 34

adhesive

Back 34

property in which a substance will cling to polar substances

Front 35

acid

Back 35

substance that completely disassociates in water and releases hydrogen ions

Front 36

base (alkaline)

Back 36

hydrogen ion acceptors or hydroxide ion donor

Front 37

pH scale

Back 37

a scale used to indicate the acidity or alkalinity of a solution

Front 38

buffer

Back 38

chemical(s) that work to keep pH within normal limits