Chapter 2 Flashcards
1
Q
required by an organism in only minute qualities
A
Trace elements
2
Q
smallest unit of matter that still retains the properties of an element
A
Atom
3
Q
where protons and neutrons are packed tightly together
A
Atomic Nucleus
4
Q
number of protons
A
Atomic Number
5
Q
total number of protons and neutrons in the nucleus of an atom
A
Mass Number
6
Q
different atomic forms of the same element
A
Isotopes
7
Q
Which is the most common isotope?
A
carbon-12
8
Q
loss of subatomic particles
A
Decay
9
Q
C-12 and C-13 are _____ isotopes?
A
stable
10
Q
one in which the nucleus decays simultaneously, giving off particles and energy
A
Radioactive Isotope
11
Q
change in the number of protons, it transforms the atom to an atom of a different element
A
What happens when radioactive decay occurs?
12
Q
Radioactive tracers are…
A
important diagnostic tools in medicine
13
Q
Only _________ are involved in the chemical reactions between atoms
A
electrons
14
Q
the capacity to cause change by doing work
A
Energy
15
Q
the energy that matter possesses because of its location or structure
A
Potential Energy
16
Q
The third electron has the least or most energy?
A
most
17
Q
electrons on the outermost shell
A
Valence Electrons
18
Q
outermost electron shell
A
Valence Shell
19
Q
Elements with full valence shells are chemically….
A
unreactive
20
Q
What are the elements with full valence shells?
A
helium
neon
argon
21
Q
What are the strongest kinds of covalent bonds?
A
Ionic covalent
Sigma covalent
22
Q
the sharing of a pair of valence electrons by two atoms
A
Covalent Bond
23
Q
two or more atoms held together by covalent bonds
A
Molecule
24
Q
when atoms share two pairs of valence electrons
A
Double Bond
25
a combination of two or more different elements
Compound
26
the attraction of a particular atom for the electrons of a covalent bond
Electronegativity
27
a covalent bond between two atoms of the same element, the electrons are shared equally because the two atoms have the same electronegativity
Nonpolar Covalent Bond
28
when atoms of the same element are bonded to a more electronegative atom, the electrons of the bond are not shared equally
Polar Covalent Bond
29
______ is one of the most electronegative elements
oxygen
30
two resulting oppositely charged atoms or molecules
Ions
31
when cations and anions attract each other
Ionic Bond
32
________ and ___________ interactions are crucial to life
hydrogen and vanderwaals
33
noncovalent attraction between a hydrogen and an electronegative atom
Hydrogen Bond
34
In living things, electronegative partners are usually.....
oxygen and nitrogen atoms
35
ever changing regions of positive and negative charge that enable all atoms and molecules to stick to one another
Van der Waals Interaction
36
A molecule consisting of two atoms is always ....
linear
37
A water molecule is shaped like a
V
38
A methane molecule has a geometric shape of a
tetrahedron
39
it determines how biological molecules recognize and respond to one another with specificality
Why is molecular shape crucial to biology?
40
the making and breaking of chemical bonds, leading to changes in the composition of matter
Chemical Reactions
41
Matter is conserved in a chemical reaction
reactions cannot create or destroy atoms but can only rearrange the electrons among them
42
cohesive behavior
ability to moderate temperature
expansion upon freezing
versatility as a solvent
Four Emergent Properties of Water
43
Cohesion
the hydrogen bonds that hold water together
44
the clinging of one substance to another
Adhesion
45
a measure of how difficult it is to stretch or break the surface of a liquid
Surface Tension
46
The specific heat of water is measured in
1 calorie per degree celsius
( 1 cal/g C)
47
PH decreases as __ increases
H+
48
Basic solutions are above...
7
49
Most biological fluids are between
6 and 8
50
Elements most essential to life
Carbon
Hydrogen
Nitrogen
Oxygen
Phosphorus
Sulfur
51
the average mass number of all isotopes of a given element
Atomic Mass
52
The chemical behavior of an atom is determined by the number of ________ in its outermost shell
electrons
53
the bonding capacity of an atom
Valence
54
An _______ force holds atoms together within a molecule
intramolecular
55
An _____ force exists between different molecules
intermolecular
56
bond that holds the O and H atoms within a water molecule
polar covalent
57
bond thats found between the partial charges of different water molecules
hydrogen bond
58
The innermost electron shell of an atom can hold up to __ electrons
2
59
Which of these relationships is true of an uncharged atom?
the number of protons is equal to the number of electrons
60
What determines the types of chemical reactions that an atom participates in?
the number of electrons in the outermost electron shell
61
Prokaryotic cells are found in the domains
bacteria and archaea
62
A human is classified in domain_____ and kingdom______
eukarya
animalia
63
A rose bush is classified in the domain _____ and kingdom _____
eukarya
plantae
64
Which domain includes unicellular organisms?
archaea
65
Fungi are classified into which domain
Eukarya
66
There is ___ eukaryotic domain
one
67
The unequal sharing of electrons within a water molecule makes the water molecule
polar
68
The tendency of an atom to pull electrons toward itself is referred to as its
electronegativity
69
In this molecule, what type of bond is found between the oxygen and the hydrogens?
polar covalent
70
Which one of these bonds is the weakest?
d- the hydrogen bond
71
Mass of 1 amu
neutron
proton
72
Mass 1/2000 amu
electron
73
Why is the increasing amount of carbon dioxide being taken up by oceans a cause for concern?
More carbon dioxide causes an increase in carbonic acid which leads to a decrease in the concentration of a carbonate ion
74
The number of protons in an uncharged atom
equals the number of electrons
75
Isotopes of an element will always differ in
atomic mass
76
A covalent bond will be polar if
one of the atoms sharing electrons is more electronegative
77
Hydrophillic substances, but not hydrophobic substances
have charges or partial charges to which water molecules can adhere
78
Ionic bonds form as a result of
attraction between ions that have opposite charges
79
Which of the following has a negligible mass?
electron
80
How many electrons would be present in the valence shell of a sulfur atom ( atomic number 16, mass number 32)
six electrons
81
A solution of pH 6 contains _______ than the same amount of solution at pH 8
100 times more H+
82
An atom that normally has _______ in its outer shell would not form chemical bonds with other atoms
eight electrons
83
Sweat has a cooling effect because of water's high
heat of vaporization
84
There are ______ naturally occurring elements
92
85
An acid is
a substance that donates hydrogen ions to a solution
86
Which of the following is a trace element?
copper
87
This depicts
A covalent bond
88
Bonds between hydrogen and oxygen are called
polar covalent bonds
89
A water molecule is...
polar
90
Water molecules attached to each other are bonded by
hydrogen bonds
91
Each water molecule can attach to ____ other water molecules
four
92
high capacity to store heat
high boiling heat
surface tension
Characteristics of water
93
pH scale expresses...
the concentration of hydrogen ions in a solution
94
an _____ is any substance that increases the hydrogen ion ( H+) concentration of a solution
acid
95
a ____ is any substance that reduces the hydrogen ion concentration
base
