Biology Test Ch. 2

Question 1

Chemistry - the study of…

Answer 1

structure and behaviors of atoms and molecules

Question 2

4 main classes of biological molecules

Answer 2

• carbohydrates
• lipids
• proteins
• nucleic acids

Question 3

Elements

Answer 3

pure substances in periodic table

Question 4

H
Atomic #?
Atomic mass?

Answer 4

Hydrogen

• atomic # = 1
• atomic mass = 1

Question 5

Ag

Answer 5

Silver

Question 6

O
Atomic #?
Atomic mass?

Answer 6

Oxygen

• atomic # = 8
• atomic mass = 16

-HAS COVALENT BONDS

Question 7

Compounds

Answer 7

combinations of elements

Question 8

CO2

Answer 8

carbon dioxide

Question 9

HCl

Answer 9

hydrochloric acid

Question 10

living organisms are made up of what elements? (6)

Answer 10

(C) arbon
(H) ydrogen
(O) xygen
(P) hosphorus
(S) elenium
(N) itrogen

Question 11

ATOMS =

Answer 11

• protons
• neutrons
• electrons

Question 12

Nucleus

Answer 12

• set # of protons

- # neutrons may very

Question 13

Atomic number

Answer 13

-# of protons (in nucleus)

-

Question 14

Atomic mass (AMU) =

Answer 14

protons + # neutrons

Question 15

First energy shell can hold…

Answer 15

2 e-

Question 16

Second energy shell can hold…

Answer 16

8 e-

***LIKE TO HAVE 8 ELECTRONS IN OUTTER SHELL

Question 17

Inner shells are filled before

Answer 17

outer shells

Question 18

Isotopes

Answer 18

same form of element, w/ different #’s of neutrons

Question 19

Radioactive isotopes

Answer 19

unstable, may emit energy when changes to a stable form

Question 20

Ions

Answer 20

ATOMS with + or - charges

ex. H+, Cl-

Question 21

Molecules

Answer 21

2 or more atoms bonded together

Question 22

Covalent Bonds

Answer 22

• atoms share pairs of e-

- FOUND IN MOLECULES

Question 23

Non-polar Bonds

Answer 23

e- shared EQUALLY

ex. O2, CH4

Question 24

Polar Bonds

Answer 24

e- shared UNEQUALLY

 ex. H2O

Question 25

Ionic Bonds

Answer 25

- bonds btwn oppositely charged ions | ex. salt

Question 26

Hydrogen Bonds

Answer 26

-when a partially (+) HYDROGEN is attracted to partially (-) ATOM

Question 27

Hydrogen Bonding makes...

Answer 27

life possible

Question 28

Hbonds affect physical...

Answer 28

- properties of water - why water is slow to heat - unusual amount of heat is required to evaporate water ex. sweating

Question 29

**Behavior of water is affected by...

Answer 29

cohesion and adhesion

Question 30

Cohesion

Answer 30

like molecules cling together

Question 31

Adhesion

Answer 31

UNLIKE molecules cling together

Question 32

Ice is LESS dense than...

Answer 32

- water - floats on water ex. frozen layer of a lake

Question 33

Water is a

Answer 33

solvent

Question 34

Solvent

Answer 34

does the dissolving

Question 35

Solute

Answer 35

- dissolves in solvent | ex. polar molecules, ions

Question 36

HydroPHILIC

Answer 36

- dissolves in water | ex. salt, sugar

Question 37

HydroPHOBIC

Answer 37

does NOT dissolve in water ex. oil, fats

Question 38

Acids

Answer 38

release H+ when dissolved in water

Question 39

Base

Answer 39

accepts H+ when dissolved in water

Question 40

Acidi pH #'s

Answer 40

0 - 7

Question 41

Basic pH #'s

Answer 41

7 - 15

Question 42

Neutral pH #

Answer 42

7

Question 43

Buffers

Answer 43

- moderate changes in pH - absorb or release H+ ex. bicarbonate/carbonic acid buffering system in blood

Question 44

Neutrons =

Answer 44

atomic mass - atomic #

Question 45

neutrons =

Answer 45

atomic mass - atomic #

Question 46

Hbonds are ______ than covalent bonds

Answer 46

WEAKER

Question 47

Mass is always the BIGGER...

Answer 47

in periodic table

Question 48

Hydrogen Bonds are usually...

Answer 48

-btwn 2 different molecules

Question 49

______ bonds allow bugs to walk on water

Answer 49

hydrogen

Question 50

Water is an example of ______ bond

Answer 50

Polar

Question 51

Salt has _____bonds

Answer 51

Ionic