C0 Chemical literacy Flashcards
what are the 7 core units in the SI system?
- mass
- length
- time
- electrical current
- temperature
- amount of substance
- light intensity
what are the units for mass in the SI system?
grams, g
what are the units for length in the SI system?
metre, m
what are the units for time in the SI system?
seconds, s
what are the units for electrical current in the SI system?
amperes, A
what are the units for temperature in the SI system?
kelvin, K
what are the units for amount of substance in the SI system?
moles, mol
what are the units for light intensity in the SI system?
candela, cd
what are derived units?
units defined by the core units in a system of equations
eg.
area is metres squared (derived from length)
10¹² prefix
tera, T
10⁹ prefix
giga, G
10⁶ prefix
mega, M
10³ prefix
kilo, k
10² prefix
hecto, h
10¹ prefix
deca, da
10⁻¹ prefix
deci, d
10⁻² prefix
centi, c
10⁻⁶ prefix
micro, μ
10⁻⁹ prefix
nano, n
10⁻¹² prefix
pico, p
10⁻¹⁵ prefix
femto, f
10⁻¹⁸ prefix
atto, a
when referring to volume in concentrations, what unit should be used?
litres, L
NOT decimetres
what are 1mL, 1L and 1000L in decimetres cubed?
- 1L = 1dm³
- 1000L = 1m³
- 1mL = 1cm³
what is the difference between molar and mole?
- molar is the unit of concentration (M)
- mole is the unit of amount of substance (mol)
what is 1M in concentration?
1 M = 1 mol/L
what are isotopes?
- same atomic number
- different mass number
- different number of neutrons
what is the mass of an atom expressed as? (the unit, what it is equivalent to and its symbol)
- ‘unified atomic mass units’
- 1 unified atomic mass unit = 1/12 of the mass of an atom of carbon-12
- symbol: u
what is the numerical value of Avogadro’s constant?
6.022 x 10^23
why is there a difference between the theoretical mass of a carbon-12 atom (12.094 atomic mass units) and the actual mass (12 atomic mass units)?
- the differences resembles the energy which is released when the subatomic particles (protons, neutrons and electrons) come together to form the atom
- the difference (0.094 atomic mass units) is called the mass deficit/mass defect
