(1) atomic structure and the periodic table Flashcards
what is the mass of a neutron
1
what is the mass of a proton
1
what is the mass of an electron
negligible (often 0)
in a nuclear symbol for an atom, where would you find the atomic and mass numbers
atomic number = bottom left
mass number = top left
what is the plum pudding model
a ball of positive charge with electrons stuck in it throughout
when is fractional distillation used
to separate a mixture of liquids e.g. crude oil
why did Mendeleev leave gaps in his periodic table
so that elements with similar properties could stay in the same groups
where are non metals found in the periodic table
at the far right and top
why does reactivity increase as you go down group 1
the outer electron is more easily lost as the attraction between the nucleus and electron decreases, because the electron is further away from the nucleus the further down the group you go
what decreases as you go down group 1
melting and boiling points
which group is known as the alkali metals
group 1
what are 3 differences between group 1 metals and transition metals
group 1 metals: are more reactive are much less dense are much less strong are much less hard have much lower melting points (except mercury)
why does reactivity decrease as you go down group 7
it is harder to gain an extra electron as the outer shell is further from the nucleus
what increases as you go down group 7
melting and boiling points
what are halides
halides are halogen ions that have bonded ionically with metals
