Elements of Life Flashcards
when AgNO3 is added to Br- ions what will happen
a cream precipitate will form
when AgNO3 is added to I- ions what will happen
yellow precipitate formed
when AgNO3 is added to Cl- ions what will happen
white precipitate formed
what is the empirical formula
The simplest whole number ratio of atoms/elements in a molecule
what is water of crystallisation
H2O molecules can be present with an ionic lattices
What does anhydrous mean
It doesn’t contain water
What does hydrated mean
it contains water
which is the strongest IMF
hydrogen bonds
which is the weakest IMF
ID-ID
ionisation energy increases…
across a period
ionisation energy increases across a period because…
there are more protons/electrons so greater nuclear charge as e- are going to same main shell
greater nuclear charge means…
(ionisation energy)
there is stronger nuclear attraction
stronger nuclear attraction leads to…
(ionisation energy)
higher 1st ionisation energy as harder to remove electrons
When group 2 reacts with H2O what is produced
hydroxides
Group 2 burns in oxygen to form…
oxides
group 2 can neutralise..
acuds
in emission spectra energy is..
released as electrons fall from excited to ground state
in absorption spectra energy is…
absorbed, promoting electrons from ground state to excited
which halide is insoluble in ammonia
iodine
which halide ion in soluble in excess ammonia
bromide ions
which halide ion is soluble in a few drops of ammonia
chloride ions
which have higher boiling pints straight or branched chain molecules
straight
what are isotopes?
isotopes of an element are atoms with the same atomic number but different mass number
do isotopes have the same chemical properties as other isotopes of that element?
yes
what did JJ Thompson propose about the atom?
plum pudding model
what was the plum pudding model?
positively charged sphere with electrons embedded within
what experiment did Rutherford do?
fired alpha particles at a think sheet of gold. some were deflected slightly but most passed through
what did the Bohr model propose?
• e- exist in fixed orbits
• each shell has fixed energy
how can relative masses be measured?
using a mass spectrometer
how can we work out relative atomic mass?
from mass spectrum data
what is avogadro’s constant?
6.02 x 10^23
number of moles =
number of particles you have / avogadro’s constant
moles=
(conc)
concentration x volume
1000 cm3 in dm3 is?
1cm3
what is the flame colour for copper
blue
what is the flame colour for sodium
orange-yellow
what is the flame colour for barium
green
what is the flame colour for calcium
brick red
what is the flame colour for potassium
lilac
what is the flame colour for lithium
crimson
how does heating crystals in a hot flame produce colour?
the heat energy excited electrons so they emit light when they fall
how many electrons can a p orbital hold?
2
what feature of an atoms structure was deduced from the Geiger and Marsden eperiment?
the nucleus is small and dense
down the group the first ionisation energies of group 2 elements..
decrease
down the group the thermal stability of carbonates with group 2 compounds…
increase
