final review Flashcards
density
mass / volume
chemical property
ability of a substance to react or change into one or more other substances (flammability or reactivity)
physical change
a change that does not alter the composition of a material, only the state or phase has changed (cut, tear, boil, freeze, grind)
chemical change
a change that alters the identity of a material, new substances are formed (burn, rot, rust)
identify chemical change
change in color, change in energy or temp, production of gas, or formation of a precipitate
types of pure substances
elements and compoundsp
types of mixtures
hetero and homogenous
number of neutrons in an atom
mass num - protons
number of protons in an atom
atomic number
number of electrons in an atom
protons (atomic number) if neutral
what is an isotope
atoms of the same element that have the same amt of protons but different amt of neutrons
isotope notation
mass num / atomic num
isotope name
element-mass num
wavelength
λ - shortest distance between equivalent points on a wave (m, mm, nm)
frequency
v - number of waves that pass a given point per second (herzt, 1/sec)
where are metals located
left of the stairstep (minus hydrogen)
where are metalloids located
on the stairstep (minus aluminium)
where are nonmentals located
right of stairstep (plus hydrogen)
group 1
alkalai metals
group 2
alkaline earth metals
group 17
halogens
group 18
noble gases
representative elements
s and p blcok
transition metals
d block
inner transition metals
f block
diatomic elements
br, i, n, cl, h, o, f
atomic size / radius
one half the distance between the nuclei of identical atoms that are bonded together
atomic size trend
largest is bottom left (francium), smallest is top right
ionization energy
energy to remove one electron
ionization energy trend
most in top right, least in bottom left
electronegativity
ability of an atom in a chemical compound to attract electrons from another atom in the compound
electronegativy trend
highest top right, lowest bottom left
elements with a set charge
cadmium (ii), zinc (ii), and silver (i)
ionic compound
trade electrons, metal and nonmetal, large electronegativy difference, acids
covalent compound
share electrons, nonmetals, small electronegativy difference
vsepr
valence shell electron pair repulsion, thoery about shape and repelling
linear vs bent
if there are no lone pairs on the central atom, it is linear (np) if there are lone pairs, it is bent (polar)
pyramiddle vs triagonal planar
pyramiddle has a lone pair (polar) triagonal planar has no lone pair (np)
octet rule exceptions
H(2), Be(4), B(6), Al(6), S(10/12), P(10/12)
electronegativy charge for types of bonds
ionic >1.7
polar covalent 0.4 - 1.7
nonpolar covalent <0.4
ionic traits
high melting points, most dissolve in water, hard and brittle, conductors, crystalline at room temp
covalent traits
lower melting points, most do not dissolve in water, soft and not brittle, not conductors, any state (rarely crystal)
london dispersion forces
weakest of the forces, in all
dipole dipole forces
in polar molecules
hydrogen bonding forces
hydrogen atom that is bonded to o, f, or n
empirical vs molecular formula
empirical is basic, molecular is multiple of empirical
emperical formula
g / (g/mol) to get moles, then divide by smallest amt
