Chapter 2- The nature of molecules and the properties of water Flashcards

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1
Q

Understanding the _______ of atoms is critical to understanding the nature of biological molecules

A

Structure

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2
Q

Atomic number is the number of _______

A

Protons

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3
Q

What determines the atoms atomic mass?

A

The sum of protons and neutrons

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4
Q

Refers to the force of gravity exerted on a substance

A

Weight

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5
Q

Any substance in the universe that has mass and occupies space

A

Matter

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6
Q

All matter is composed of extremely small particles called _______

A

Atoms

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7
Q

Hydrogen contains _______ proton and _______ electron

A

1;1

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8
Q

Oxygen has _______ protons neutrons and electrons

A

8

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9
Q

The mass of atoms and subatomic particles is measured in units called _______

A

Daltons

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10
Q

Any substance that can’t be broken down to any other substances by chemical means

A

Element

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11
Q

_______ are charged atoms

A

Ions

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12
Q

A _______ has more protons than electrons so it has a positive charge

A

Cation

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13
Q

An _______ has fewer protons than electrons so it has a negative charge

A

Anion

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14
Q

Where electrons are located at varying distances around the nucleus

A

Orbitals

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15
Q

Atoms of a single element that possess different numbers of neutrons

A

Isotopes

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16
Q

_______ isotopes are unstable and emit radiation as the nucleus breaks up

A

Radioactive

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17
Q

The time it takes for 1/2 of the atoms in a sample to decay

A

Half life

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18
Q

The key to the chemical behavior of an atom lies and the number and arrangement of its _______ in their orbitals

A

Electrons

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19
Q

The _______ model of the atom shows individual electrons as following distinct circular orbits around a central nucleus

A

Bohr

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20
Q

Almost all of the volume of an atom is _______ space

A

Empty

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21
Q

No oral can contain more than _______ electrons

A

2

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22
Q

Electrons have potential energy related to their _______

A

Position

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23
Q

Are electrons farther from the nucleus have _______ energy

A

More

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24
Q

Energy levels indicate _______ while orbitals indicate _______

A

Energy; location

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25
Q

During some chemical reactions, electrons can be _______ from one atom to another

A

Transferred

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26
Q

Chemical reactions that result in the loss of an electron

A

Oxidation

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27
Q

Reaction that results in the gain of an electron

A

Reduction

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28
Q

When the process of oxidation and reduction are coupled, which happens often, one atom or molecule is oxidized, while another is produced in the same reaction, which is called _______ _______

A

Redox reactions

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29
Q

The periodic table displays elements according to _______ electrons

A

Valence

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30
Q

_______ electrons are the number of electrons in the outer most energy level

A

Valence

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31
Q

_______(nonreactive) elements have all eight electrons or full orbitals

A

Inert

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32
Q

The rule that Adams tend to establish completely full outer energy levels

A

The octet rule

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33
Q

Full outer energy levels have _______ filled S orbital and _______ filled P orbitals

A

1;3

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34
Q

_______ electrons and they are interactions are the basis for the different chemical properties of elements

A

Valence

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35
Q

_______ only needs two electrons to fill the 1 S orbital

A

Helium

36
Q

There are ______ naturally occurring elements

A

90

37
Q

Only _______ elements are found in living organisms in substantial amounts

A

12

38
Q

Four elements make up _______% of human body weight

A

96.3

39
Q

The four elements that make up 96.3% of the human body weight

A

Carbon, hydrogen, oxygen, nitrogen

40
Q

_______ molecules contain primarily CHON(carbon, hydrogen, oxygen, nitrogen)

A

Organic

41
Q

_______ are groups of atoms held together in a stable association

A

Molecules

42
Q

_______ are molecules containing more than one type of element

A

Compounds

43
Q

Atoms are held together in molecules or compounds by _______ bonds

A

Chemical

44
Q

Bonds that result when atoms with opposite charges attract each other

A

Ionic

45
Q

Bond that forms when two atoms share one or more pairs of electrons

A

Covalent

46
Q

Electrical attraction of water molecules can _______ forces holding ions together

A

Disrupt

47
Q

Na atom _______ an electron to become Na+

A

Loses

48
Q

Cl atom _______ an electron to become Cl-

A

Gains

49
Q

Opposite charges attract so that in Na+ and Cl- remain associated as an _______ compound

A

Ionic

50
Q

_______ bonds formed when two atoms share one or more pairs of valence electrons

A

Covalent

51
Q

Strength of covalent bond depends on the number of shared _______

A

Electrons

52
Q

The molecule formed by the two hydrogen atoms is stable for three reasons:

A

It has no net charge
The octet rule is satisfied
It has no unpaired electrons

53
Q

The _______ formula of hydrogen gas and oxygen gas and hydrogen gas are H-H and O=O and their _______ formulas are H2 and O2

A

Structural;molecular

54
Q

_______ is created by an atoms affinity for electrons

A

Electronegativity

55
Q

In general, electronegativity increases _______ to _______ across a row of the periodic table and decreases down the column

A

Left;right

56
Q

Elements in the upper-right corner have the _______ electronegativity

A

Highest

57
Q

_______ covalent bonds = equal sharing of electrons

A

Nonpolar

58
Q

_______ covalent bonds = unequal sharing of electrons

A

Polar

59
Q

The formation and breaking of chemical bonds is called a _______ _______

A

Chemical reaction

60
Q

The _______ of water allows water molecules to be attracted to one other and other molecules

A

Polarity

61
Q

The extent to which chemical reactions occur is influenced by three important factors:

A

Temperature
Concentration of reactants and products
Catalysts 

62
Q

A _______ is a substance that increases the rate of a reaction

A

Catalyst

63
Q

Single most outstanding chemical property of water is its ability to form _______ bonds

A

Hydrogen

64
Q

Within a water molecule, the bonds between oxygen and hydrogen are highly _______

A

Polar

65
Q

Oxygen is much _______ electronegative than hydrogen

A

More

66
Q

Oxygen has a partial _______ charge while hydrogen has a partial _______ charge

A

Negative;positive

67
Q

Cohesion of liquid water is responsible for its _______ tension

A

Surface

68
Q

An example of a nonpolar molecule/substance would be _______ because it can’t get “wet” like polar molecules

A

Oil

69
Q

6 properties of water:

A

High specific heat
High heat of vaporization
Solid water is less dense than liquid water
Is a good solvent
Organizers nonpolar molecules
Can form ions

70
Q

Water causes hydrophobic molecules to aggregate or assume specific _______

A

Shapes

71
Q

The energy required to increase the surface area is known as _______ _______

A

Surface tension

72
Q

Hydrogen bonding affects _______, The attraction of water molecules to a solid phase

A

Adhesion

73
Q

The measure of how rapidly a substances individual molecules are moving

A

Temperature

74
Q

The amount of heat 1 g of a substance must absorb or lose to change its temperature by 1°C

A

Specific heat

75
Q

Because polar substances tend to form hydrogen bonds, the more _______ it is, the higher is it’s specific heat

A

Polar

76
Q

Because of it’s high specific heat, _______ heats up more slowly than almost any other compound and holds its temperature longer

A

Water

77
Q

The amount of energy required to change 1 g of a substance from a liquid to a gas

A

Heat of vaporization

78
Q

The tendency of nonpolar molecules to aggregate in wither

A

Hydrophobic exclusion

79
Q

The weight of a substance in grams that corresponds to the atomic masses of all of the atoms in a molecule of that substance

A

A mole

80
Q

_______ Is the negative logarithm of hydrogen ion concentration of solution

A

pH

81
Q

Pure water is _______(pH 7)

A

Neutral

82
Q

Any substance that disassociates in water to increase the hydrogen concentration

A

Acid

83
Q

The stronger an acid is, the more _______ ions it produces and the lower its pH

A

Hydrogen

84
Q

Substances that combine with hydrogen dissolved and water and the slowers the hydrogen concentration

A

Base

85
Q

Compound that resist changes in pH

A

Buffers

86
Q

In acid, buffers work by _______ hydrogen ions when a base is added

A

Releasing

87
Q

And a base, buffers work by _______ hydrogen ions when acid is added

A

Absorbing