chapter 2: The Chemical Context of Life Part 1

Question 1

matter

Answer 1

anything that takes up space and has mass

Question 2

element

Answer 2

a substance that cannot be broken down by other substances by chemical reactions

Question 3

compound

Answer 3

substance consisting of 2 or more elements in a fixed ratio (different elements)

Question 4

what four elements make up 96% of all living matter?

Answer 4

C-H-O-N

Question 5

essential element

Answer 5

needed by an organism to live a healthy life and reproduce

Question 6

trace element

Answer 6

required in only minute quantities

Question 7

neutron

Answer 7

no electric charge

Question 8

proton

Answer 8

positive charge

Question 9

electron

Answer 9

negative charge

Question 10

atomic number

Answer 10

unique number of protons

Question 11

atomic mass

Answer 11

atom’s total mass can be approximated by the mass number

Question 12

isotope

Answer 12

2 atoms of an element that differ in number of neutrons

Question 13

electron shells

Answer 13

an electron’s state of potential energy

Question 14

energy

Answer 14

the capacity to cause change to do work

Question 15

what makes forms the atomic nucleus?

Answer 15

neutrons and protons

Question 16

what do electrons do to a nucleus?

Answer 16

form a cloud around it

Question 17

how do you determine the mass number

Answer 17

protons + neutrons

Question 18

radioactive isotopes

Answer 18

decay and give off particles and energy

Question 19

what are radioactive isotopes used for

Answer 19

-dating fossils
-tracing atoms
-medical diagnoses

Question 20

which is the only subatomic particle that is directly involved in the chemical reactions between atoms?

Answer 20

electrons

Question 21

potential energy

Answer 21

the energy that matter has because of its location or structure

Question 22

what determines the chemical behavior of an atom?

Answer 22

determined by the distribution of electrons in electron shells

Question 23

covalent bond

Answer 23

the sharing of a pair of valence electrons by 2 atoms (non-metal and non-metal) (share electrons)

Question 24

molecule

Answer 24

2 or more atoms held together by valence bonds (one element)

Question 25

pure elements

Answer 25

composed of molecules of one type of atoms (H2)

Question 26

structural formula

Answer 26

H-H

Question 27

molecular formula

Answer 27

H2

Question 28

electronegativity

Answer 28

an atom's attraction for the electrons in a covalent bond

Question 29

non-polar covalent bond

Answer 29

atoms share electrons equally

Question 30

polar covalent bond

Answer 30

atoms do not share electrons equally (one atom is more electronegative)

Question 31

cation

Answer 31

positively charged ion

Question 32

anion

Answer 32

negatively charged ion

Question 33

hydrogen bond

Answer 33

a weak bond between 2 molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other

Question 34

ionic bond

Answer 34

attraction between a cation and anion (usually metal and non-metal) (transfer of electrons

Question 35

van der Waals interactions

Answer 35

attractions between molecules that are close together as a result of these charges

Question 36

strongest to weakest bonds

Answer 36

1.covalent 2.ionic 3.van der Waals 4.hydrogen

Question 37

molecular shape

Answer 37

determines how biological molecules recognize and respond to one another

Question 38

what type of molecule is water?

Answer 38

polar molecule

Question 39

polar molecule

Answer 39

one side that is positively charged and one side that is negatively charged

Question 40

mixture

Answer 40

physically mixed together but not chemically combined

Question 41

what charge does hydrogen atoms have in a molecule of water?

Answer 41

positive

Question 42

what charge do oxygen atoms have in a molecule of water?

Answer 42

negative

Question 43

2 types of mixtures

Answer 43

homogeneous and heterogeneous

Question 44

solute

Answer 44

what dissolves

Question 45

solvent

Answer 45

dissolves solute (water is the greatest)

Question 46

cohesion

Answer 46

an attraction between molecules of the same substance

Question 47

adhesion

Answer 47

an attraction between molecules of different substances

Question 48

capillary

Answer 48

the tendency of water to rise in a thin tube

Question 49

surface tension

Answer 49

allows water to hold up materials heavier and denser than itself

Question 50

heat of vaporization

Answer 50

quantity of heat a liquid must absorb for 1 gram to be converted from liquid to a gas