First Quarter Review Flashcards
dependent variable
output of the independent variable
plotted on the y-axis
hypothesis
an educated guess about how things work
form: if__ then__
independent variable
a variable that is controlled by scientist
plotted on x-axis
qualitative data
data that describes how? and what?
quantitative data
data that describes how many? or how much?
has numbers
matter
anything that has mass and takes up space
mass
the amount of matter in an object
measure of inertia
chemical property
a property of matter that describes a substance’s ability to participate in chemical reactions
ex. inflammability
chemical change/reaction
a change that occurs when one or more substances change into entirely new substances with different properties
ex. wood burning, carbon and oxygen(2) form carbon dioxide, sour milk
physical property
a characteristic of a substance that does not involve a chemical change
ex. density, color, hardness
physical change
a change of matter from one form to the other without a change in chemical properties
ex. salt dissolving in water
all changes in state are physical changes
atom
the smallest particle in which an element can be divided and still be the same substance
atomic number
the number of protons
identifies the element
determines chemical properties
isotopes
atoms that have the same number of protons but have different number of neutrons
same atomic number different mass number
atoms of the same element with different masses
mass number
number of protons + number of neutrons
electron
the negatively charged particles in an atom
likely found in the electron cloud
mass: tiny
energy levels
max. # of electrons of each level
a layer of electrons formula for finding max # of electrons of each level: 2n^2 1st- 2 2nd- 8 3rd- 18 4th- 32
valance electrons
electrons on the outermost shell of electron cloud
determines the atom’s chemical properties
proton
positively charged particle
found in the nucleus
mass: 1+
neutron
no charge particle
found in nucleus
mass: 1amu
slightly bigger mass than proton
gas
the state of matter does not have a definite volume or shape
disorganized
far apart
move in straight line until they bounce off something else
lot of energy
liquid
the state of matter that has a definite volume but not a definite shape
particles slide past each other
disorganized
solid
the state of matter in which the volume and shape of a substance are fixed
particles are close together
organized
move by vibrating
fluids
liquid
gas
plasma
boiling
when a liquid turns into a gas
freezing
when a liquid turns into a solid
melting
when a solid turns into liquid
condensation
when a gas turns into a liquid
sublimation
when a solid turns into a gas
deposition
when a gas turns into a solid directly
substance
matter that has uniform and unchanging properties
cannot be separated by physical changes
compound
a pure substance composed of two or more elements chemically combined
can be broken down by chemical reactions(means)
definite ratio of components
element
a pure substance that cannot be broken down by physical or chemical means
mixture
a combination of two or more substances that are not chemically combined
2 or more components that keep their physical characteristics
can be separated by physical means(changes)
2 types: heterogeneous and homogeneous
solution
homogeneous mixture smaller part: solute largest part: solvent can't be filtered or settled out on standing can't scatter light
solute
smaller part of solution
dissolved into solvent
solvent
largest part of solution
solute dissolves into solvent
colloid
heterogeneous mixture can't be separated by filtration can't settle out on standing can scatter light (Tyndall effect ex. jello, fog, whipped cream
suspension
heterogeneous mixture can be separated by filtration settles out on standing can't scatter light ex. chocolate, orange juice w/ pulp, snow globe
particle size
smallest: solution- smaller than light waves
larger: colloid- bigger than light waves but not big enough to see
largest: suspension- big enough to see
heterogeneous mixture
not uniformly mixed unequal distribution of parts you can see different parts 2 kinds: suspension and colloid when broken breaks into pieces
homogeneous mixture
uniformly mixed
same as solution
molecule
the smallest unit of a substance that keeps all of the physical and chemical properties of that substance
held together by covalent bonds
Covalent Bonding
Mechanism?
Bond?
Atom kind need?
when two elements share valence electrons
electron sharing
the nuclei’s attraction for the shared electrons
non-metal
naming covalent compounds
first word- prefix if more than one (of element) and element name (never use mono- on first word)
second word- prefix & element root & “ide”
NO CRISSCROSS!!!
no double vowels so drop a vowel (unless it is an “i”)
Ionic Bonding
Mechanism?
Bond?
Atom kind needed?
bonding with ions
electrons transfer
attraction of the positive cation and the negative anion
non-metal and metal
naming ionic compounds
first word- name the cation (keep name of parent ion)
second word- name the anion (change ending to “ide”)
inert
chemically non-reactive
noble gases are inert
Metallic Bonding
Atom kind needed?
the bond is the attraction of the nuclei for “sea of valence electrons” or “giant valence electron cloud”
metal
cation
positively charged ion
losing electrons
more protons
anion
negatively charged ion
gains electrons
more electrons
period/series
same # of?
horizontal row of elements on the periodic table
principle energy levels
group/family
same # of?
vertical column of elements on the periodic table
valence electrons
Law of Conservation of Energy
states that energy cannot be created or destroyed through ordinary chemical or physical changes but can be converted into other forms
Law of Conservation of Matter
states that matter cannot be created or destroyed in ordinary chemical and physical changes
Density equation
D=m/V m=mass V=volume m=D x V V=m/D
Law of Conservation of Charges
states that charges cannot be created or destroyed in ordinary chemical or physical changes
alkaline earth elements
group 2 on the periodic table lose 2 electrons bond:2+ metal properties metallic bonding and ionic bonding
halogens
the seventeenth group in the periodic table gain 1 electron bond: 1- nonmetal properties covalent bonding and ionic bonding
gases: chlorine, fluorine
liquids: bromine
alkali elements
group 1 on the periodic table lose 1 electron bond: 1+ metallic bonding and ionic bonding metal properties
transition elements
groups 3-12 on the periodic table
metallic bonding and ionic bonding
inner transition elements
both rows on the bottom of the periodic table
metal properties
make cations
noble gases
group 18 on the periodic table don't share, gain, or lose electrons (octet rule) inert colorless odorless gases
metals
left of the zigzag line shiny ductile good conductors of electric current malleable good conductors of thermal energy
metalloids
border the zigzag line shiny brittle hard but brittle good conductor of electric current
rare earth elements
1st row on the bottom of the periodic table
acid
any compound that increases the number of hydronium ions (H3O+), when dissolved in water (hydronium is greater than hydroxide)
pH<7
electrolytes, solutions conduct electricity
sour taste
not slippery
reacts with metals to produce hydrogen gas
base
any compound that increases the number of hydroxide ions (OH-), when dissolved in water (hydroxide is greater than hydronium)
bitter taste
has slippery solutions
electrolytes, solutions conduct electricity
nonmetals
right of the zigzag line not malleable or ductile not shiny poor conductors of thermal energy and electric current (opposite of metal) brittle
pH
measure of concentration of hydronium ions H3O+
reactant
the starting substance or molecule in a chemical reaction
product
the new substances that forms in a chemical reaction
neutral
pH=7
number of hydronium ions equal the number of hydroxide ions
synthesis reaction
a reaction in which two or more substances combine to form a new compound
A+X-AX
single product
decomposition
a reaction in where a single compound breaks down to form two or more simpler substances
one compound-2 or more substances
AX-A+X
reactant is compound
yield
(arrow)
single-replacement reaction
a reaction in which one element takes the place of another element in a compound
an element and a compound-a different element and compound
A+BX-B+AX(cation replacement), or Y+BX-X+BY(anion replacement)
double-replacement reaction
a reaction in which a gas, a solid precipitate, or molecular compound forms from the exchange of ions between two compounds
two compounds-two different compounds
AX+BY-AY+BX
combustion
substance + oxygen
oxygen is a reactant, product is oxides, light, and heat
product of hydrocarbon is CO2 and H2O
ex. 2H2+O2-2H2O
nucleon
protons or neutrons
nuclide
single type of nucleus (a specific number of protons and neutrons)
radioactivity
process by which an unstable nucleus releases particles and/or energy to get to a stable energy state
radioactive
describes a nucleus in an unstable state
radiation
the particles of energy given off by a radioactive nucleus
alpha (symbols, mass #, charge,etc.)
a, a2+, ^4 2He2+, ^4 2He mass #= 4 charge=2+ helium nucleus not much energy is given off, sheet of paper can shield alpha particles alpha increases proton-neutron ratio
beta (symbols, mass#, charge, etc.)
B, B-, e-, ^0 -1e mass #= 0 charge= 1- high energy electron decreases proton-neutron ratio
gamma (symbol, mass #, charge, etc.)
Y mass #= 0 charge= 0 electromagnetic energy waves proton-neutron ratio stays same
positron
same mass as electron, positive charge
band of stability
as the # of protons increases, the # of neutrons required to stabilize the nucleus increases too
if there are too many protons or neutrons, the nucleus is not stable
to get to a stable energy state, unstable nucleus undergoes a nuclear reaction, has to have a mass of 1-1.5 to be stable
half life
the time needed for half of a sample of a radioactive substance to undergo radioactive decay
to get age of substance after decay, x the # of half-lives that have passed by the half-life of the substance
writing formulas for ionic compounds
- write the ions including charge
- if ion charges match- only write the symbols
- if ion charges don’t match- Crisscross (where you switch the ion charges)
Law of Conservation of Matter and Energy
E=mc^2
E=energy
m=matter
c=constant
