atom structure and the periodic table

Created by

Lee

Cards (13)

element  
all of the atoms are the same
compound
two or more different atoms chemically bonded together
mixture
different elements or compounds which are not chemically bonded to each other
molecule
has any elements combined
filtration
used to separate an insoluble solid from a liquid
pour mixture into filter paper
the liquid passes through the tiny pores (filtrate), solids are trapped
simple distillation
evaporate liquid by heating
condense vapour back into liquid by cooling
fractional distillation
gently heat mixture
when the vapours reach the fractionating column they condense and drip back into the flask where the liquids evaporate again
increases the amount of lower boiling point chemical in the fractionating column
pass into a condenser and turn into liquid
collected in a fresh beaker
nuclear model
empty space
negative electrons surrounding the positive nucleus
modified nuclear model
niels bohr proposed electrons orbited the nucleus at specific distances
energy levels or shells
several years later, protons were discovered, determines amount of positive charge
james chadwick discovered that the nucleus also contained neutral particles, neutron
radius is of an atom is 0.1 nanometres
radius of nucleus is 1 times 10 (-14)
relative charges
proton +1
neutron 0
electron -1
relative mass
proton 1
neutron 1
electron very small
plum pudding model
in 1897, electrons discovered
atom is a ball of positive charge with negative electron embedded in it
alpha scattering experiment, scientist took a piece of gold foil, then fired alpha particles with positive charge.
most particles went through without changing direction (empty space), sometimes, they were deflected (centre must have a positive charge), sometimes, bounced straight back off (centre of atom contains a great deal of mass)
replaced plum pudding model with a nuclear model