chemistry end of year

Question 1

what particles are in an atom (1,2,3)

Answer 1

1 protons: are heavy and positively charged
2 neutrons: are heavy and neutral
3 electrons: have hardly any mass

Question 2

is in the middle of an atom
contains protons and neutrons
has a positive charge becuase of protons
almost the whole mass of atom is concentrated in the …….!
compared to the overall size of the atom the ………! is tiny

Answer 2

nucleus

Question 3

……… move around the nucleus in energy levels called shells
there negatively charged.
there tiny but there orbitals cover a lot of space
the size of there orbitals determine the size of the atom.
…….. have no mass

Answer 3

electrons

Question 4

neutral atoms have no charge overall
the charge on the ……. is the same size as the charge on the ……… - but opposite
this means the number of …… always equals the number of …….. in a nuetral
if some ….. are added or removed the atom gets charged and is then an ION

Answer 4

number of electrons = number of protons

Question 5

atoms join together to form ……..
some ……. molecules are made from just one element (E.G. H2, N2) while others are made up of more than one element (E.G. H2O, CO2)

Answer 5

molecules are groups of atoms

Question 6

explain the meaning of the term isotopes

Answer 6

isotopes are different atomic forms of the same element which have the same number of protons but different number of nutrons