Chemistry Unit Test

matter

anything that has mass and occupies spaces

mass

quantity of matter an object has

weight

pull of gravity on an object

element

substance made of one kind of atom

period

horizontal rows and tell number of valence electrons

group

vertical groups

6 elements necessary for life

carbon, hydrogen, oxygen, nitrogen, phosphorous, sulfur

element symbol

unique on/two letter symbol

atomic number

number of protons and sometimes electrons

atomic mass

sum of protons and neutrons

nucleus

\-middle of atom

\-holds positive charged protons and neutral neutrons

\-overall has positive charge

\-contains most of mass of atom

protons

all atoms of given element have same number of protons

neutrons

number varies slightly among atoms of the same element

isotopes

an element w/ same number of protons but different number of neutrons

eletrons

negatively charged high energy particles w/ little to no mass

\
travel at very high speeds in diff energy levels (energy levels different distances from nucleus)

electron cloud

make of shells:

innermost.....can hold almost 2e-

next most.....can hold at most 8e-

third outermost.....can hold at most 18e-

octet rule

atoms tend to gain, lose, or share electrons so as to have 8 electrons

ion

a charged atom. two types are anions and cations. become charged due to adding or removing electrons

neutral atom:

has same number of protons and electrons

anion

\-negatively charged atom

\-atoms gain electrons

\-more e- than p+

cation

\-positive charge

\-atoms lose (e-) electrons

more p+ than e-

what holds atoms together?

chemical bonds

3 main types of bonds

\-ionic

\-covalent

\-hydrogen

coefficient

number in front\=many atoms or molecules

subscript

number behind and below a letter

molecules

\-2+ atoms covalently bonded together

\-almost all substances that make up organisms, are molecules held together by covalent bonds

\-type of compound (not all compounds are molecules though)

compounds

\-2+ elements bonded together

\-different properties than individual elements

covalent bonds

formed when two atoms share 2+ electrons

called molecules

between 2 nonmetals

ionic bonds

\-formed when one more electrons transferred from metal to nonmetal

between 2 nonmetals

\-atoms that gained or lost electrons are called ions

level of organization

subomatic particles

atoms

elements

molecule

macro molecules

cell

tissue

organ

organ system

organism

electronegativity

the tendency of an atom to attract electrons in a bond

what is an atoms's electronegativity affected by?

both atomic \# and distance valence electrons are from the nucleus

the higher the associated electronegativity....

the more an atom or a substance or a substance root attracts electrons

pauling scale

Measures electronegativity

carbon pauling scale

2.55

hydrogen pauling scale

2.20

oxygen pauling scale

3.44

nitrogen pauling scale

3.09

phosphorus pauling scale

2.19

sulfur pauling scale

2.58

electronegativity differences

provides another way of predicting kind of bond that will form elements

electronegativity differences nonpolar covalent

0.0 to 0.2

electronegativity differences polar covalent

0.3 to 1.4

electronegativity differences ionic

\>1.5

polar molecules

unequal distribution of charges

\-one side positive

\-one side negative

\-dissolves in water

nonpolar molecules

no separation of charge, no positive or negative poles formed

\-don't dissolved in water

what are hydrogen atoms with partial positive charged attracted to?

oxygen atom with partial negative charge of a different water molecule!

\-known as a Hydrogen bond

hydrogen bonds

bonding between polar molecules

\-very weak

\-while covalent bonds internally hold water molecules together, different water molecules are held externally by very weak hydrogen bonds

5 characteristics of water

cohesion, adhesion, high specific heat, less dense as a solid, water is a terrific solvent

cohesion

Attraction between molecules of the same substance

\-tendency of molecules of same "kind" to stick together

\-causes high surface tension

adhesion

An attraction between molecules of different substances

\-forms stronger bonds than cohesion

high specific heat

The ability of water to resist changes in temperature

\-helps regulate cell temperature in organisms which allows life to live in water and moderates earth's climate

less dense as a solid

solid water (ice) is less dense than liquid water

\-therefore ice floats in liquid water

water is a terrific solvent

A solution is a mixture of substances looks the same throughout

\-water is a universal solvent

hydrophilic

\-has affinity for water

\-water “loving”

\-dissolves in water

\-salt and sugar (ex)

hydrophobic

\-no affinity for water

\-water “fearing”

\-not dissolve in water

\-oil (ex)

macromolecules

large molecules that are formed by joining smaller organic molecules together

organic

compounds that contain carbon

monomers

small, basic unit

polymers

complex structure made of monomers

hydrolysis

Breaking down complex molecules by the chemical addition of water

carbohydrates

\-short term energy

\-structure and support

\-found in sugar and starch

\-made of C,H,O

\-energy storage: 4

carb monomers and polymers

monomer- monosaccharides

polymer- polysaccharide

lipids

\-long term energy storage

\-cushioning organs, insulation, hormones, cell membrane

\-found in fats, oils, phospholipids, steroids

\-made of C,H,O

\-energy storage: 9

lipids monomer and polymer

monomer- no "true" monomer, but mostly fatty acids

polymer- fats, oils, phospholipids, steroids,k hormones

phospholipid

a lipid that contains phosphorus and that is a structural component in cell membranes

protein

\-most diverse and abundant macro

\-found in meats, nuts, yogurt, etc.

\-made of CHNOPS

\-energy storage- 4 cal/Mg

protein functions

1. enzymes control rate of chemical reactions
2. hormones regulate cell processes
3. used to form bones and muscles
4. transports substances in and out of cells
5. antibodies help fight diseases
6. food source

Protein monomer and polymer

Monomer: amino acids

Polymer: polypeptide

nucleic acids

\-store and transmit heredity or genetic info

\-example is DNA and RNA

\-made of C,H,N,O,P

nucleic acids monomer and polymer

monomer: nucleotide

Polymer: nucleic acid

reactants\`

substances that undergoes chemical reactions and always are written on the left side of the arrow

products

new substance formed from chemical reaction. always written on the right side of the arrow

rules to balancing equations

1. subscripts can’t be added, removed, or changed
2. only change coefficients


1. coefficients can only go in the front of chemical formulas

chemical reactions

1. different types of chemical reactions


1. depending on how atoms rearrange themselves in chemical reactions, we give the reaction a different name

types of chemical reactions

synthesis, decomposition, combustion, single replacement, double replacement

synthesis

two or more substances form a compound

A+B=AB

decomposition

compound broken down into simpler substances (compound to elements)

AB=A+B

combustion

fuel burns in presence of oxygen forming water and carbon dioxide

single replacement

element will swap places with an atom in a compound

AB+C=AC+B

double replacement

ions swap partners

AB+CD=AD+CB

factors that affect reaction rates

concentration, temperature, surface area,

concentration

higher concentration of reactants leads to more collisions of that reactant (so it speeds up the reaction)

temperature

increase in temperature raises the average kinetic energy of reactant molecules

surface area

increasing surface area by pounding it flat or cutting it in many pieces will increase the reaction rate