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

Question 1

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

Answer 1

Structure

Question 2

Atomic number is the number of _______

Answer 2

Protons

Question 3

What determines the atoms atomic mass?

Answer 3

The sum of protons and neutrons

Question 4

Refers to the force of gravity exerted on a substance

Answer 4

Weight

Question 5

Any substance in the universe that has mass and occupies space

Answer 5

Matter

Question 6

All matter is composed of extremely small particles called _______

Answer 6

Atoms

Question 7

Hydrogen contains _______ proton and _______ electron

Answer 7

1;1

Question 8

Oxygen has _______ protons neutrons and electrons

Answer 8

8

Question 9

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

Answer 9

Daltons

Question 10

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

Answer 10

Element

Question 11

_______ are charged atoms

Answer 11

Ions

Question 12

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

Answer 12

Cation

Question 13

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

Answer 13

Anion

Question 14

Where electrons are located at varying distances around the nucleus

Answer 14

Orbitals

Question 15

Atoms of a single element that possess different numbers of neutrons

Answer 15

Isotopes

Question 16

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

Answer 16

Radioactive

Question 17

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

Answer 17

Half life

Question 18

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

Answer 18

Electrons

Question 19

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

Answer 19

Bohr

Question 20

Almost all of the volume of an atom is _______ space

Answer 20

Empty

Question 21

No oral can contain more than _______ electrons

Answer 21

2

Question 22

Electrons have potential energy related to their _______

Answer 22

Position

Question 23

Are electrons farther from the nucleus have _______ energy

Answer 23

More

Question 24

Energy levels indicate _______ while orbitals indicate _______

Answer 24

Energy; location

Question 25

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

Answer 25

Transferred

Question 26

Chemical reactions that result in the loss of an electron

Answer 26

Oxidation

Question 27

Reaction that results in the gain of an electron

Answer 27

Reduction

Question 28

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 _______ _______

Answer 28

Redox reactions

Question 29

The periodic table displays elements according to _______ electrons

Answer 29

Valence

Question 30

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

Answer 30

Valence

Question 31

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

Answer 31

Inert

Question 32

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

Answer 32

The octet rule

Question 33

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

Answer 33

1;3

Question 34

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

Answer 34

Valence

Question 35

_______ only needs two electrons to fill the 1 S orbital

Answer 35

Helium

Question 36

There are ______ naturally occurring elements

Answer 36

90

Question 37

Only _______ elements are found in living organisms in substantial amounts

Answer 37

12

Question 38

Four elements make up _______% of human body weight

Answer 38

96.3

Question 39

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

Answer 39

Carbon, hydrogen, oxygen, nitrogen

Question 40

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

Answer 40

Organic

Question 41

_______ are groups of atoms held together in a stable association

Answer 41

Molecules

Question 42

_______ are molecules containing more than one type of element

Answer 42

Compounds

Question 43

Atoms are held together in molecules or compounds by _______ bonds

Answer 43

Chemical

Question 44

Bonds that result when atoms with opposite charges attract each other

Answer 44

Ionic

Question 45

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

Answer 45

Covalent

Question 46

Electrical attraction of water molecules can _______ forces holding ions together

Answer 46

Disrupt

Question 47

Na atom _______ an electron to become Na+

Answer 47

Loses

Question 48

Cl atom _______ an electron to become Cl-

Answer 48

Gains

Question 49

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

Answer 49

Ionic

Question 50

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

Answer 50

Covalent

Question 51

Strength of covalent bond depends on the number of shared _______

Answer 51

Electrons

Question 52

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

Answer 52

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

Question 53

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

Answer 53

Structural;molecular

Question 54

_______ is created by an atoms affinity for electrons

Answer 54

Electronegativity

Question 55

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

Answer 55

Left;right

Question 56

Elements in the upper-right corner have the _______ electronegativity

Answer 56

Highest

Question 57

_______ covalent bonds = equal sharing of electrons

Answer 57

Nonpolar

Question 58

_______ covalent bonds = unequal sharing of electrons

Answer 58

Polar

Question 59

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

Answer 59

Chemical reaction

Question 60

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

Answer 60

Polarity

Question 61

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

Answer 61

Temperature Concentration of reactants and products Catalysts 

Question 62

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

Answer 62

Catalyst

Question 63

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

Answer 63

Hydrogen

Question 64

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

Answer 64

Polar

Question 65

Oxygen is much _______ electronegative than hydrogen

Answer 65

More

Question 66

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

Answer 66

Negative;positive

Question 67

Cohesion of liquid water is responsible for its _______ tension

Answer 67

Surface

Question 68

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

Answer 68

Oil

Question 69

6 properties of water:

Answer 69

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

Question 70

Water causes hydrophobic molecules to aggregate or assume specific _______

Answer 70

Shapes

Question 71

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

Answer 71

Surface tension

Question 72

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

Answer 72

Adhesion

Question 73

The measure of how rapidly a substances individual molecules are moving

Answer 73

Temperature

Question 74

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

Answer 74

Specific heat

Question 75

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

Answer 75

Polar

Question 76

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

Answer 76

Water

Question 77

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

Answer 77

Heat of vaporization

Question 78

The tendency of nonpolar molecules to aggregate in wither

Answer 78

Hydrophobic exclusion

Question 79

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

Answer 79

A mole

Question 80

_______ Is the negative logarithm of hydrogen ion concentration of solution

Answer 80

pH

Question 81

Pure water is _______(pH 7)

Answer 81

Neutral

Question 82

Any substance that disassociates in water to increase the hydrogen concentration

Answer 82

Acid

Question 83

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

Answer 83

Hydrogen

Question 84

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

Answer 84

Base

Question 85

Compound that resist changes in pH

Answer 85

Buffers

Question 86

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

Answer 86

Releasing

Question 87

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

Answer 87

Absorbing