Chapter 2 - Chemical Foundation of Life

Question 1

What are the 4 main elements of living organisms?

Answer 1

Carbon
Hydrogen
Oxygen
Nitrogen

Question 2

All living things have a large percentage of ______________

Answer 2

Water

Question 3

These cannot be broken down into simpler substances - they form all matter

Answer 3

Elements

Question 4

One major thing that viruses lack?

Answer 4

No cell membrane - not cells

Question 5

Life on our planet started from a _______

Answer 5

Single-celled organism

Question 6

Smallest unit of an element

Answer 6

Atoms

Question 7

Atoms are made up of 3 things

Answer 7

Protons
Electrons
Neutrons

Question 8

What orbits around the nucleus?

Answer 8

Electrons

Question 9

The ________ the electron is from the nucleus, the greater the amount of energy. (farther/closer)

Answer 9

Farther

Question 10

Electrons occupy _________ _________ and orbit around the ___________

Answer 10

Electron shells
Nucleus

Question 11

All atoms will be either ________ or _________

Answer 11

Stable or reactive

Question 12

What holds atoms together in molecules?

Answer 12

Chemical bonds

Question 13

Name 3 types of chemical bonds.

Answer 13

1. Ionic Bonds
2. Covalent Bonds
3. Hydrogen Bonds

Question 14

Number of protons equal what?

Answer 14

Number of electrons

Question 15

Two types of covalent bonds

Answer 15

1. Nonpolar Covalent bonds
2. Polar Covalent bonds

Question 16

What are Nonpolar Covalent bonds?

Answer 16

Chemical bond where 2 atoms share electrons equally - not charged

Question 17

What are Polar Covalent bonds?

Answer 17

Electrons are shared UNEQUALLY between two atoms - charged

Question 18

The electrical attraction between positively and negatively charged ions form a(n):
a. covalent bond
b. Hydrogen bond
c. ionic bond
d. oxygenated bond

Answer 18

Ionic bond

Question 19

Which of the following describes a nonpolar covalent bond?
a. unequal sharing of electrons
b. charged
c. loss of electrons
d. equal sharing of electrons

Answer 19

Equal sharing of electrons

Question 20

How many covalent bonds can be made by 2 electrons on first circle and 4 electrons on second circle?

Answer 20

4 - trying to get to 8

Question 21

What are 2 important properties of water?

Answer 21

Cohesion
Adhesion

Question 22

What is cohesion?

Answer 22

Sticks to itself - causes surface tension

Question 23

What is adhesion?

Answer 23

sticks to other things / molecules

Question 24

Another important property of water?

Answer 24

Solvent

Question 25

What is a solvent?

Answer 25

dissolves - using a solution ex. salt

Question 26

What is another name for "water-loving?"

Answer 26

Hydrophilic

Question 27

What is hydrophobic? Give examples.

Answer 27

Water-fearing - fats, oils, phospholipids

Question 28

What will resist temperature changes longer than the atmosphere?

Answer 28

Water

Question 29

Explain why water has a high HEAT OF VAPORIZATION?

Answer 29

Energy input must be high enough to break hydrogen bonds AND allow liquid to evaporate

Question 30

What forms an unusual solid?

Answer 30

Water / Ice

Question 31

Ponds, rivers, ocean - freezes .... a. From bottom to top b. From top to bottom

Answer 31

b. From top to bottom (that's why aquatic life can live below)

Question 32

pH scales measures what?

Answer 32

Hydrogen ions

Question 33

What are the pH measures? 0-6 7 8-14

Answer 33

0-6 / acidic 7 / neutral 8-14 / basic

Question 34

What does it mean if something is too acidic - to add a base and bring closer back to neutral?

Answer 34

To buffer

Question 35

Water is _______ in pH.

Answer 35

Neutral

Question 36

Pure water is neutral in pH because a. concentration of oxygen and hydrogen is equal b. concentration of hydroxide ions and hydrogen ions is equal

Answer 36

The concentration of hydoxide ions and hydrogen ions is equal.

Question 37

Sweating is a useful cooling device for humans because ___________

Answer 37

Water takes up a great deal of heat in changing from its liquid state to its gaseous state