January Science League

mass measurement unit

kilograms (kg)

length unit

meters m

temperature unit

kelvin k

amount unit

moles mol

current unit

amperes a

intensity

candelas cd

fahrenheit to celsius

C(9/5) + 32

celsius to fahrenheit

(5/9)(F-32)

celsius to kelvin

c + 273.15

how many atoms in 1 mol

6.022 × 10²³

mass to moles

moles = mass (g)/molar mass (g/mol)

moles to mass

mass = moles x molar mass

moles to particles

particles = moles x avogadro’s number

particles to moles

moles = particles / avogadro’s number

mass to particles

particles = (mass/molar mass) x avogadro’s number

particles to mass

mass = (particles/avogadro’s number) x molar mass

moles to volume for gases at stp

volume (L) = moles x 22.4L/mol

volume to moles for gases at stp

moles = volume/22.4

finding current

i = Q/t, i= current in amperes, q = electric charges in coulombs, t = time in seconds

finding electric charge

Q = it

ohm’s law

i=v/r

power and current

i=p/v, p = power in watts, v = voltage in volts

current in parallel circuits

i>total = i>1+i>2+i>3+…, i>1,2,3 = currents in individual branches, i>total = total current

luminous intensity

i=lm/sr, i= luminous intensity in candelas, lm = luminous flux in lumens, sr = solid angle in steradians

luminous flux

lm = i(sr)

relationship between luminance and intensity

i=la, l = luminance in cd/m², a = proected area of the source in m²

luminous intensity and distance

e=i/d², e = illuminance in lux, d = distance from the light source in meters

weight percent

wt = (mass of solute/mass of solution)x100

in significant figures, non-zero digits are […] significant

always

in significant figures, zeroes between significant figures […] significant

are

in significant figures, leading zeroes […] significant

are not

in significant figures, trailing zeroes […] significant if there is a decimal

are

an extensive property is

dependent on the amount of matter of an object

an intensive property is

independent from the amount of matter of an object

synthesis reaction

a+b → ab

decomposition reaction

ab→a+b

single replacement reaction

a+bc→ac+b

double replacement reaction

ab+cd→ad+cb

what is a combustion reaction

a hydrocarbon reacts with oxygen to make carbon dioxide and water

metal activity series: please stop calling me a zebra in nice tiny little happy classrooms singing gracefully

K>Na>Ca>Mg>Al>Zn>Fe>Ni>Sn>Pb>H>Cu>Ag>Au

non metal activity series": funny owls chase big icy spiders carefully and patiently

F>O>Cl>Br>I>S>C>P

a metal will […] a metal or another hydrogen in a compound if higher in the metal activity series

replace

if the element is lower in the reactivity series, […] will occur

no reaction

if higher on the metal activity series, a metal can […] another metal from its ion solution in a redox reaction

displace

metals […] hydrogen can react with water to produce a metal hydroxide and hydrogen gas

above

metals above hydrogen […] with acids

will react

metals lower in the activity series are less reactive and […] corrosion

resist

metals […] in the activity series decompose

lower

in a galvanic cell, the […] element is the anode and the […] element is the cathode

higher, lower