Atoms, Molecules, and Water (2)

Question 1

atom

Answer 1

smallest functional units of matter that form all chemical substances
cannot be further broken down
each specific type is a chemical element

Question 2

3 subatomic particles

Answer 2

protons (+), neutrons (neutral), electrons (-)

Question 3

protons

Answer 3

of protons distinguishes elements
atomic number = number of protons
also = to # of electrons so net charge is 0

Question 4

periodic table

Answer 4

organized by atomic number
rows = periods (number of electron shells)
columns = groups (number of valence electrons)

Question 5

valence electrons

Answer 5

number of electrons in outer shell

Question 6

orbitals

Answer 6

hold electrons
each can only hold up to 2
reside in electron shells

Question 7

atomic mass

Answer 7

protons and neutrons are nearly equal in mass

Question 8

dalton

Answer 8

measurement for atomic mass (aka amu)
1 Da = 1/12 mass of carbon atom or mass of Hydrogen atom

Question 9

mole

Answer 9

1 mole contains same number of atoms — 6.022 x 10^23 (avogadros number)

Question 10

isotopes

Answer 10

multiple forms of an element that differ in number of neutrons

Question 11

elements of life

Answer 11

hydrogen, oxygen, carbon, nitrogen (HOCN), mineral elements, trace elements

Question 12

molecule

Answer 12

two or more atoms held together by chemical bonds

Question 13

compound

Answer 13

any molecule composed of two or more elements

Question 14

molecular formula

Answer 14

contains chemical symbols of the elements in the molecule with the number of each shown

Question 15

types of bonds

Answer 15

covalent, hydrogen, ionic

Question 16

covalent bond

Answer 16

electrons are SHARED to fill valence shells (can be polar or non polar)
share a pair of electrons
strong and energetically stable
between atoms with unfilled valence electron shells

Question 17

hydrogen bond

Answer 17

hydrogen atom from one polar molecule is ATTRACTED to an electronegative atom from another molecule
weak electrostatic bonds between Hydrogens w/ partial (+) charge and atoms with partial (-) charges
responsible for structure of DNA and protein

Question 18

ionic bond

Answer 18

electrons are TRANSFERRED, forming ions that are attracted to each other

when a cation binds to an anion by electrostatic (charge) attraction

Question 19

octet rule

Answer 19

atoms are stable (in a low energy state) when their outer shell is full
for atomic number >2, outer shell is filled with 8 electrons

Question 20

electronegativity

Answer 20

a measure of an atom’s ability to attract electrons
differences dictate how electrons are distributed in covalent bonds

Question 21

non polar covalent

Answer 21

equal sharing of electrons
atoms with similar electronegativities
no charge difference across molecule

Question 22

polar covalent

Answer 22

unequal sharing of electrons
unequal distribution creates a polarity (difference in electric charge)
ex. water

Question 23

ion

Answer 23

atom or molecule that has gained or lost one or more electrons

Question 24

cation

Answer 24

has a net positive charge

Question 25

anion

Answer 25

have a net negative charge

Question 26

properties of chemical reactions

Answer 26

require source of energy, an enzyme, will eventually reach equilibrium, proceed in certain direction, most often in liquid

Question 27

solution

Answer 27

solute dissolved in a particular solvent

Question 28

solute

Answer 28

substance being dissolved

Question 29

solvent

Answer 29

liquid in which they’re dissolved

Question 30

aqueous solutions

Answer 30

solutions in which water is solvent

Question 31

hydrophilic

Answer 31

polar and charged molecules (“water loving”)
ex. salt, sugar

Question 32

hydrophobic

Answer 32

non polar molecules (“water fearing”)
ex. fats and oils

Question 33

amphipathic molecules

Answer 33

have polar and non polar ends (“both loves”)

Question 34

functions of water

Answer 34

chemical reactions
provides force and support
removes toxic waste from body
evaporative cooling
cohesion and adhesion
surface tension
lubrication

Question 35

kinetic energy

Answer 35

energy of motion

Question 36

heat

Answer 36

a measure of the total quantity of kinetic energy due to molecular motion in a body of matter

Question 37

temperature

Answer 37

the average kinetic energy of molecules

Question 38

heat of vaporization

Answer 38

energy required to turn water to water vapor

Question 39

specific heat

Answer 39

amount of energy required to raise temp by 1C

Question 40

heat of fusion

Answer 40

energy released when water is frozen

Question 41

evaporative cooling

Answer 41

as a liquid evaporates, the surface of the liquid that remains behind cools

Question 42

cohesion

Answer 42

tendency of H2O molecules to stick together
“stickiness to itself”

Question 43

adhesion

Answer 43

tendency of H2O molecules to stick to other molecules
“stickiness to other stuff”

Question 44

surface tension

Answer 44

cohesion of water

Question 45

capillary action

Answer 45

water “crawls” up capillaries
ex. how water goes from tree roots to leaves

Question 46

acids

Answer 46

molecules that RELEASE hydrogen ions in solution

Question 47

bases

Answer 47

lower the H+ concentration

Question 48

pH scale

Answer 48

<7 = acidic
7 = neutral
>7 basic/alkaline