LO2

Question 1

Atomic number =

Answer 1

protons ; # electrons

Question 2

If a number neutrons is changed it will also change the

Answer 2

Atomic mass

Question 3

Anions (negatively charged atoms) have

Answer 3

More electrons than protons

Question 4

The outer (valence) electron energy level of an atom

Answer 4

Contains electrons at the highest energy level

Question 5

Strong attractive force resulting from the sharing of electrons between atoms

Answer 5

Covalent bonds

Question 6

Weak attractive force joining nonpolar molecules over a short distance

Answer 6

Van de Waals interaction

Question 7

Bond results from the transfer of electrons between atoms; strong in the absence of water but weak in aqueous solutions

Answer 7

Ionic bonds

Question 8

Weak attractive force joining a hydrogen atom with an electronegative atom such as oxygen; holds adjacent water molecules together

Answer 8

Hydrogen bond

Question 9

Two elements that are highly electronegative; do NOT share electrons equally when bonded with other elements

Answer 9

Oxygen and nitrogen

Question 10

Molecule of water characteristics

Answer 10

• shared electrons will be pulled more towards the O atom
• the O atom has a partial negative charge
• there is a partial positive charge at each H atom

Question 11

When one atom transfers an electron to another atom they form

Answer 11

An ionic bond between a cation and anion

Question 12

Single water molecule is formed by

Answer 12

Polar covalent bonds

Question 13

Liquid and ice water are formed by

Answer 13

Hydrogen bonds

Question 14

Due to high heat vaporization, a lot of heat leaves our bodies when we sweat, as water changes from

Answer 14

Liquid to gas

Question 15

Ph measures the concentration of

Answer 15

Hydrogen

Question 16

A solution containing more hydrogen (H+) ions than hydroxyl (OH-) would be

Answer 16

Acidic with pH below 7

Question 17

A solution at pH 7 is considered neutral because

Answer 17

It’s hydrogen ions equal its hydroxide ion concentration

Question 18

H+ concentration is less than 7

Answer 18

Basic solution

Question 19

In the carbonic acid buffering system, biocarbonate ions

Answer 19

Act as a weak base by removing excess hydrogen ions from the blood

Question 20

Reduction

Answer 20

Atom gains an electron

Question 21

Essential elements

Answer 21

Carbon, hydrogen, oxygen, and nitrogen

Question 22

Trace elements

Answer 22

Are necessary for life but found in small quantities

Question 23

Atomic number is determined by

Answer 23

The # of protons

Question 24

Total number of protons and neutrons in an atom is referred to

Answer 24

The atomic mass

Question 25

Atomic mass varies, Atomic number remains constant in

Answer 25

Isotopes

Question 26

Unstable isotopes that emit radiation when they decay

Answer 26

Radioisotopes

Question 27

Measure of an atoms affinity for (or ability to attract) electrons that are being shared in a chemical bond

Answer 27

Electronegative

Question 28

Covalently bonded atoms with similar electronegativities are bound together by

Answer 28

Non polar covalent bonds

Question 29

Covalently bonded atoms with differing electronegativities are bounded together by

Answer 29

Polar covalent bonds

Question 30

Bonds between positively charged cations and negatively charged anions

Answer 30

Ionic bonds

Question 31

Relatively weak, but when present in large number, they are collectively strong

Answer 31

Hydrogen bonds

Question 32

Van der Waals interactions are weak forces due to

Answer 32

the random movement of electrons

Question 33

Hydrogen bonds between adjacent water molecules

Answer 33

Cohesion

Question 34

Water molecules ability to stick to other substances via hydrogen bonding

Answer 34

Adhesion

Question 35

Helps organisms and bodies of water maintain a relatively constant internal temperature

Answer 35

Waters high specific heat

Question 36

Helps organisms and bodies of water maintain a relatively constant internal temperature

Answer 36

Waters high specific heat

Question 37

Evaporation cooling depends on the

Answer 37

High heat of vaporization

Question 38

Donates hydrogen ions to a solution

Answer 38

Acid

Question 39

Removes hydrogen ions from a solution

Answer 39

Base

Question 40

Buffer

Answer 40

Either a weak acid or weak base; resist changes in PH

Question 41

For two atoms to be the same element they must

Answer 41

Have the same number of protons

Question 42

Water has high specific heat because

Answer 42

Hydrogen bonds must be broken to raise its temperatures

Question 43

Ionic compounds and polar molecules are

Answer 43

Hydrophilic

Question 44

As the pH of a solution gets lower

Answer 44

The concentration of hydrogen ions increase; more H+ ions = lower pH = more acidic

Question 45

High pH(buffer system)

Answer 45

Carbonic acid needed to donate H+ ion lowering pH

Question 46

Low pH( buffer system)

Answer 46

Bicarbonate ion needed