semster finals stuff Flashcards
what are the two branches of science
natural and social
what are three types of natural science
physical, earth/space, life
what is the scientific method
a systematic procedure for collecting/analyzing data
5 steps of scientific method
- make observations/state the problem
- gather information
- form hypothesis
- test hypothesis
- draw conclusions
physical properties
DENSITY, color, hardness, melting point, boiling point, electrical conductivity
physical changes
melting, freezing, condensing, breaking, crushing
chemical properties
solubility, flammeability, radioactivity, acidity
chemical changes
burning, corroding, spoiling, cooking
intensive properties
does not depend on the size
extensive
depends on the size
matter is what two things?
substance and a mixture
element
a SUBSTANCE that cannot be broken down into smaller substances
compound
a combination of elements
homogenous mixture
evenly mixed
heterogenous mixture
not evenly mixed
solution
homogenous, small particles, dont separate
suspension
seperates into layers, cloudy
colloids
heterogenous, small intermediate particles (fog)
exothermic
release of heat
endothermic
absorbing heat
calculation for density
D = m/v (mass over volume)
calculation for pressure
P = f/a (pressure = foce/area)
mass number
protons and neutrons
atomic mass
protons and neutrons
atomic number
protons
dalton
billard ball model, discovered atoms
thomson
cathode ray tube, discovered electron
rutherford
gold foil experiment, discovered nucleus
bohr
bohr model (planetary atom model), discovered valence electron levels
chadwick
discovered neutrons
isotopes
same number of protons, different number of neutrons
group 1
alkali metals
group 2
alkaline earth metalsg
group 3
boron family
group 4
carbon family
group 5
nitrogen family
group 6
oxygen family
group 7
halogens
group 8
noble gases
where are metalloids? what are their properties?
stair-steps; ability to conduct heat and temperature varies with temperature
where are nonmetals? what are their properties?
right side of stairs; nonmetals are poor conductors, gases at rm temp
where are metals? what are their properties?
left side of stairs; luster, ductile, malleable, conductors, most solids
to gain full outer energy level, metals…
lose electrons
to gain full outer energy levels, nonmetals…
gain electrons
to gain full outer energy levels, metalloids…
share electrons
group
columns or families, have same number of VE
period
rows, properties change greatly across period, first element in the period is very reactive metal
trends in periodic table
atomic size decreases, metallic properties decrease, ability to lose an electron decreases, ability to GAIN an electron increases
isotope calculation
protons and neutrons
ionic bonds
share between metals/nonmetals
covalent bonds
share between nonmetals
