biology 1150 test two ( basic chemistry and water )

Question 1

which of the following has the smallest size

a. neuron
b. molecule of glucose
c. atom of oxygen
d. cell

Answer 1

a. neuron

Question 2

the number of electrons always equals

a. number of neutrons
b. number of protons and neutrons
c. number of protons
d. none of the above

Answer 2

c. number of protons

Question 3

isotopes differ in number of electrons

a. true
b. false

Answer 3

b. false

Question 4

atomic theory says

Answer 4

all living and non living things are made up of atoms

Question 5

atoms are made of

Answer 5

sub atomic particles (protons, neutrons, & electrons)

Question 6

what does the atomic number tell us

Answer 6

number of protons

Question 7

common elements found in organisms are (6)

Answer 7

carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur

Question 8

the shell closest to the nucleus can hold ___ electrons

Answer 8

2

Question 9

what does the atomic mass tell us

Answer 9

number of protons plus neutrons

Question 10

what are covalent bonds

Answer 10

when atoms share electrons

Question 10

stable atom means

Answer 10

outmost shell is full

Question 11

what are ionic bonds

Answer 11

when atoms transfer electrons

Question 12

what is a non-polar covalent bond in hydrogen molecule

Answer 12

electrons are superimposed on the bond to indicate that they are halfway between the two atoms, shared equally

Question 13

what is a polar covalent bond in water molecules

Answer 13

electrons are not shared equally so partial charges exist on the O and H atoms

Question 14

which is more electronegative

a. oxygen
b. hydrogen

Answer 14

a. oxygen

Question 15

protons have a ____ charge

Answer 15

positive

Question 16

electrons have a ____ charge

Answer 16

negative

Question 17

neutrons have ____ charge

Answer 17

no

Question 18

neutral atom has

Answer 18

same number of electrons and protons

Question 19

atoms form bonds with other atoms to ____

Answer 19

become stable

Question 20

the ____ of water makes it a great solvent

Answer 20

polarity

Question 21

how does a water molecule form

Answer 21

oxygen atom covalently bonds with two hydrogen atoms

Question 22

hydrogen bonds form because

Answer 22

hydrogen atoms from one water molecule are attracted to the oxygen atoms of other water molecules

Question 23

hydrogen bonds are _____ than covalent bonds

Answer 23

weaker

Question 24

human body is made up of ___% water

Answer 24

67

Question 25

water serves as the _____ to chemical reactions to occur

Answer 25

media

Question 26

water is polar and electrons are _____ ______ oxygen

Answer 26

pulled toward

Question 27

hydrogen bonds form between _____ molecules

Answer 27

water

Question 28

define cohesion binding

Answer 28

binding between like molecules (water to water)

Question 29

define adhesion binding

Answer 29

binding between unlike molecules (water with glass)

Question 30

transportation of materials in the blood occurs due to

Answer 30

cohesion and adhesion binding properties

Question 31

water has _____ capacity for _______ energy

Answer 31

high / absorbing

Question 32

solid water is _____ dense than liquid water

Answer 32

less

Question 33

molecules are ________ __________ in ice

Answer 33

evenly spaced

Question 34

molecules are ________ _______ in liquid form water

Answer 34

closer together

Question 35

when placed in water, acids release _______ ions

Answer 35

hydrogen

Question 36

when placed in water, bases release ________ ions

Answer 36

hydroxide

Question 37

the lower the ph the ______ the acidity

Answer 37

higher

Question 38

the higher the ph, the ______ _______ the solution

Answer 38

more basic

Question 39

water can act as both an acid and a base a. true b. false

Answer 39

a. true

Question 40

pure water pH is

Answer 40

7

Question 41

pH > 7

Answer 41

base / alkaline

Question 42

pH < 7

Answer 42

acidic

Question 43

weak bonds formed between water molecules are ______ bonds a. covalent b. compound c. hydrogen d. ionic

Answer 43

c. hydrogen

Question 44

what property of water provides the cooling effect of sweating a. cohesiveness b. high heat capacity c. high heat of vaporization d. surface tension

Answer 44

c. high heat of vaporization

Question 44

most body fluids are found in which range of the pH scale a. 1-5 b. 6-8 c. 9-14 d. all body fluids are 7

Answer 44

b. 6-8

Question 45

solution a has a pH of 6. solution b has a pH of 9. which is false a. solution a have more H+ than solution b b. solution b is basic and solution a is acid c. both solutions a and b are acids d. solution b has more OH- than H+ ions

Answer 45

c. both solutions a and b are acids