semester one exam Flashcards
three parts of an atom
protons, neutrons, electrons
what charge do protons have
positive
what charge do neutrons have
neutral
what charge do elcetrons have
negative
define an element
a pure substance made up of atoms of the same type. there are 92 naturally occuring elements
define a compound
two or more elements chemically combined. cannot be easily separated
electron configuration of first 4 shells
2n^2 first shell: 2 second shell:8 third shell:18 fourth shell:32
how many electrons can the outer most shell have
8,, after 8 electrons fill the outer shell a new shell starts and then once that one reaches 8 it goes back and fills the other shell
atomic radius increases when
you move down the periodic table
atomic radius decreases when
you move across the periodic table
ionic compounds
metals - nonmetals
covalent bonding
nonmetals - nonmetals
metalic bonding
metals-metals
cations
positive ions, generally metals, lose electrons to become positively charged with noble gas configuration
anions
negative ions, generally nonmetals, gain electrons to become negatively charged with noble gas configuration
balanced chemical equations and lewis structure
how you write chemical equations
4 observations that show a chemical reactions
change in temperature
change in colour
formation of a precipitate
light or sound given off
4 steps to a writting a balanced chemical equation
worded equation
chemical formulas
balance it using big numbers
add subscripts of states of reactants and product
particles that determine elements place in periodic table
protons and electrons
noble gases
have full outer shells and are stable
(aq)
aquius solution, elements or compounds disolved in water or solution
increaing surface area to volume ratio does
it exposes more area of the reactants to increase speed of reaction because more room for reaction to take place
combustion reactions
when methane, petrol or pentane (hydrocarbons) and oxygen react to form carbon dioxide and water
precipitation reaction
when two ionic aquius solutions combined react and form a precipitate
decompositon reaction
when a substance is brocken down using heat into simpler forms
CaCO3–>CaO + CO2
displacement reaction
when a metal is added to a ionic aquius solution and the stronger metal displaces the weaker metal out of solution
endothermic reaction
when a reaction loses heat as it takes in heat from the surroundings
exothermic reaction
when a reaction produces heat and the temperature of the reaction rises
factors that increase the rate of reaction
surface area to volume ratio
concentration
temperature
SI unit
m-meters kg-kilograms s-seconds K-kelvins N-newtons m/s-meters per second m/s/s-meters per seond per second
average speed
speed=distance/time
kelvins to celcius
+273
scalar values
have size such as distance
vector values
have both size and direction such as velocity. must give a direction
ticker timer
50 spaces/dots = 1 second
acceleration due to gravity
9.8m/s
acceleration
acceleration = final velocity-intial velocity/time
a precipitate is
a solid forming from a chemical reaction, changing the colour
force
force = mass x acceleration
m/s –> km/h
x 3.6
km/h –> m/s
divided by (/) 3.6
newtons first law
INERTIA- an objects tendency to resist changes in motion. so keep moving until something stops it or stay still until a force makes it move
newtons first law example
when a train breaks and you continue to move and fall over
newtons second law
force=mass x acceleration. an object will accelerate in the direction of an unbalance force (larger force) acting upon it. the size of the acceleration depends on the mass of the object and the size of the force acting on it.
newtons second law example
force = 60 x 9.8 = 588N. my total force when falling on earth
newtons third law
for every action force there is an equal and opposite reaction force. forces occur in pairs
newtons third law example
when a rocket takes of it pushes gases out (action force) which causes the gas to push the rocket up (reaction force).
