review

Question 1

define atomic and mass number

Answer 1

atomic number- number of protons

atomic mass- sum of protons and neutrons

Question 2

isotopes are

Answer 2

two atoms of an element that differ in the number of neutrons

Question 3

radioactive isotopes describe

Answer 3

nucleus decays spontaneously giving off particles and energy

Question 4

the unit of measure for atoms and their subatomic particles are

Answer 4

dalton

Question 5

an ion is

Answer 5

an atom that gives up or gains electrons

Question 6

molecules are when

Answer 6

two or more atoms bonded together

Question 7

a compound is

Answer 7

a substance that contains atoms of two or more different elements

Question 8

is free radical is a ___ hence why its so ___

Answer 8

atom or group of atom with an unpaired electron in the outermost shell hence why its unstable and highly reactive

Question 9

the force that holds together the atoms of a molecule or compound are

Answer 9

chemical bonds

Question 10

an atom is unlikey to form a chemical bond if

Answer 10

its valence shell is stable

Question 11

cation vs anion

Answer 11

cation- positively charged

anion- negatively charged

Question 12

describe non polar in relations to H–H

Answer 12

equal sharing of electrons, same electronegativity therefore the electrons are distribute equally

Question 13

describe polar in relations to H–F

Answer 13

unequal sharing of electrons because F is more electronegative than H, therefore the electrons in HF are going to spend more time around F rather than H, leaving F with a partial negative charge and H with a partial positive charge

Question 14

describe covalent bonds

Answer 14

when two or more atoms share electrons rather than gaining or losing them

Question 15

what’re the 2 types of covalent bonds

Answer 15

polar and nonpolar covalent bonds

Question 16

hydrogen bonds are ____ compared to ionic and covalent bond

Answer 16

weak

Question 17

the hydrogen bonds that link the neighbouring water molecules gives water considerable _____

Answer 17

cohesion

Question 18

the cohesion of water molecules create ___

Answer 18

a very high surface tension

Question 19

surface tension can be described as

Answer 19

the difficulty of stretching or breaking the surface of a liquid

Question 20

is water more attached to one another or the molecules in the air? provide an example (leaf)

Answer 20

water molecules are much more attached to one another than they are to air molecules, an example to this is how a leaf is able to float on water

Question 21

the number of atoms in each element remains the _____ before and after a chemical reaction

Answer 21

same

Question 22

chemical reactions occur when

Answer 22

new bonds form or old bonds break between atoms

Question 23

chemical energy is form of ____ energy that is stored…

Answer 23

chemical energy is a form of potential energy that is store in the bonds of compounds and molecules

Question 24

chemical bonds represent _____ energy

Answer 24

stored chemical energy

Question 25

exergonic reaction vs endergonic

Answer 25

exergonic- release more energy than absorbed | endergonic- absorb more energy than they release

Question 26

describe relationship between exergonic and endergonic reactions

Answer 26

energy released from exergonic reactions is often used to drive an endergonic one,

Question 27

a molecule of glucose broken down can produce

Answer 27

32 molecules of atp

Question 28

collision energy needed to break the chemical bond of reactants is called

Answer 28

activation energy

Question 29

factors that speed up reactions include (2)

Answer 29

conc.- the more particles of matter present in a confined space, the greater the chance that they will collide temp- as temp rises, particles of matter move about more rapidly thus the more forcefully particles will collide think of KMT

Question 30

catalysts purpose is

Answer 30

to speedd up chemical reactions by lowering activation energy

Question 31

a catalyst ____ alter the difference in potential energy between reactnts and products

Answer 31

does not

Question 32

at the end of a reaction the catalyst remains___-

Answer 32

unchanged

Question 33

not only do particles must collide they must____ a catalyst helps by

Answer 33

not only do particles must collide they must hit one another at precise spots, a catalyst helps to properly orient the colliding particles

Question 34

___ reactions are usually endergonic bc/ | ____ are usually exergonic bc/

Answer 34

anabolic reactions are usually endergonic bc they absorb more energy than they release catabolic reactions are exergonic bc they release more energy than they absorb

Question 35

anabolic vs catabolic

Answer 35

catabolic reactions break down larger molecules | anabolic reactions synthesis larger molecules from smaller parts

Question 36

oxidation refers to the ____

Answer 36

loss of electrons

Question 37

oxidation substances ____ energy

Answer 37

release

Question 38

reduction refers to

Answer 38

the gain of electrons

Question 39

reduction substances often ____ energy

Answer 39

gain

Question 40

give an ex of oxidation-reduction reactions

Answer 40

when a food molecule such as glucose is oxidized, the energy produced is used by aa cell to carry out its various function

Question 41

inorganic compounds vs organic

Answer 41

inorganic compounds lack carbon whereas organic compounds always have carbon

Question 42

water is known as the

Answer 42

universal solvent

Question 43

explain how water aids in chemical reaction

Answer 43

hydrolysis and dehydration synthesis (water removed added..etc)

Question 44

why does water have a high heat capacity

Answer 44

as water absorbs heat energy, most of the energy will be used to break its hydrogen bonds, with little energy left over to increase the motion of water molecules hence temp

Question 45

water acts as a _____ fluid

Answer 45

lubricating

Question 46

describe mixture and the 3 types of it

Answer 46

mixture- combo of elements or compound that are physically blended together but not bound by chemical bonds solutions- solutes remain evenly dispersed colloid- usuallu appear translucent or opaque, intermediate in size between solution and suspensions suspension- the suspended molecules may mix with the liquid but after some time it eventually setlles down to the bottom

Question 47

concentraion of solution can be expressed in 2 ways

Answer 47

percentage - mass per volume | molarity- moles per litre

Question 48

an acid is a ___ while base is ___

Answer 48

an acid is a proton doner while base is proton acceptor

Question 49

describe a salt when dissociated in water and provide example

Answer 49

dissociates into cation and anion which is neither of H+ or OH- example KCL = K+ and CL-

Question 50

acid and bases react with each other to form

Answer 50

salts

Question 51

alkaline vs acidic

Answer 51

alkaline= more hydroxide ions | acidic- more hydrogen ions

Question 52

a PH of 6 denotes ___ more __ than a PH of 7

Answer 52

a ph of 6 denotes 10 times more H+ than a ph of 7

Question 53

a ph of 8 denotes ____ 10 times ___ H+ than a ph of 6

Answer 53

a ph of 8 denotes 100 times fewer H+ than a ph of 6

Question 54

the ph of blood is between

Answer 54

7.35-7.45

Question 55

buffer systems function to convert ____ because

Answer 55

convert strong acid and base into weak acid and bases because strong acid and bases ionize too quickly and can contribute many H+ or OH- to the solution causing ph to change drastically

Question 56

common buffer system in our body is + chemical name

Answer 56

acid-bicarbonate buffer system (H2CO3)

Question 57

the reaction that joins 2 monomers is called

Answer 57

dehydration synthesis

Question 58

dehydration synthesis of 3 monomers will produuce __ water

Answer 58

3 waters

Question 59

which macromolecules form polymer and which dont

Answer 59

carbs, nucleic acid, and proteins form polymers while lipids dont

Question 60

cells link monomers together into polymers by ___-

Answer 60

dehhydration synthesis

Question 61

cells break polymer down to monomers by ___

Answer 61

hydrolysis

Question 62

radiocative isotopes pro and cons

Answer 62

cons- dangerous to life because it creates mutation in dna | pros- can be useful in biological research as tracers

Question 63

the farther an electron is from the nucleus the ___ it has

Answer 63

more energy

Question 64

____ bonds dissolve easily in water

Answer 64

ionic bonds

Question 65

compunds formed by _____ are not considered to be molecules

Answer 65

ionic bonds

Question 66

water is an organic or inorganic structure

Answer 66

inorganic

Question 67

atoms in which the outermost electron shell is not completely filled tend to be

Answer 67

chemically reactive