chapter 2

Question 1

matter

Answer 1

anything taking up space and mass

Question 2

element

Answer 2

substance that can’t be broken down to other substances by chemical reactions

Question 3

compound

Answer 3

substance consisting of two or more elements

Question 4

essential elements

Answer 4

elements needed for an organism to survive

Question 5

trace elements

Answer 5

required by organisms by certain amounts

Question 6

atom

Answer 6

smallest unit of matter that retains properties of an element

Question 7

atomic number

Answer 7

number of protons and electrons in neutral atom

Question 8

mass number

Answer 8

total number of protons and neutrons

Question 9

neutrons

Answer 9

mass - atomic

Question 10

isotopes

Answer 10

same number of protons but more neutrons resulting in more mass

Question 11

decay

Answer 11

tends to lose subatomic particles

Question 12

radioactive isotope

Answer 12

nucleus decays spontaneously giving off energy and particles

Question 13

half-life

Answer 13

time for 50% of parent isotope to decay

Question 14

radiometeic dating

Answer 14

calculate how many half lives have passed since fossilization

Question 15

energy

Answer 15

capacity to cause change (doing work)

Question 16

potential energy

Answer 16

energy matter has due to location

Question 17

valence electrons

Answer 17

outermost electron

Question 18

inert

Answer 18

elements having full valence shells (chemically unreactive)

Question 19

chemically reactive

Answer 19

elements having incomplete valence shells

Question 20

orbital

Answer 20

3D shape where electrons are found 90% of the time

Question 21

covalent bond

Answer 21

sharing of a pair of valence electrons by two atoms

Question 22

molecule

Answer 22

two or more atoms held by covalent bonds

Question 23

atoms valence

Answer 23

bonding capacity and equals the number of electrons needed to complete the valence shell

Question 24

compound

Answer 24

combination of two or more diff elements

Question 25

electronegativity

Answer 25

increases from bottom left corner to top right corner of periodic table. it is the attraction of a atom for electrons of a covalent bond

Question 26

nonpolar covalent bond

Answer 26

when electrons shared equally bc of the same electronegativity

Question 27

polar covalent bond

Answer 27

two atoms having different electro negativities so electrons aren’t shared equally and varied polarity

Question 28

ions

Answer 28

oppositely charged atoms

Question 29

cation vs anion

Answer 29

cations are positive and lose electrons and anions are negative and gain electrons

Question 30

ionic bond

Answer 30

cations and anions attract each other

Question 31

ionic compounds/salts

Answer 31

compounds formed by ionic bonds

Question 32

hydrogen bonds

Answer 32

no covalent attraction between hydrogen and an electronegative atom (FON)

Question 33

van der waals

Answer 33

individually weak and occur when atoms are close

Question 34

molecular shape

Answer 34

determines how biological molecules recognize and respond to another’s specificity

Question 35

chemical equilibrium

Answer 35

point where reactions offset one another

Question 36

equilibrium

Answer 36

doesn’t meant equal concentration but concentrations are STABILIZED at a ratio