chemistry
the number of protons found in the nucleus of an atom
atomic number
a physical process turning a liquid to its gaseous state by raising the temperature above its boiling point
boiling
the processes of changing a substance from solid to liquid and from liquid to gas, and also the reverse of these processes
changes of state
a property of matter, can be positive or negative, which attract each other
charge
the process of turning gas to liquid
condensation
the point separating whole numbers from the value indicating the amount of 1/10ths or 1/100ths represented
decimal point
a physical process turning a gas directly to its solid state
deposition
the length of the largest line across a circle, the line goes through the midpoint. The maximum width of a sphere.
diameter
negatively charged subatomic particle with negligible mass
electron
an area around the nucleus which will probably hold electrons. It is not a physical 'hard ring' but a model of an area where
electrons may be 'found'. An energy level
electron shell
a Nobel Laureate scientist working in Manchester and Cambridge who proposed that the atom had a nucleus with electrons
surrounding it and that the atom was mostly empty space
Ernest Rutherford
an experiment using the scattering of alpha particles on gold leaf that showed that some particles were
deflected by a concentrated charge leading to the idea of an atom with a nucleus
Geiger and Marsden experiment
atoms with the same number of protons but different numbers of neutrons
isotope
discovered the electron and suggested the plum pudding model of an atom
J.J. Thomson
discovered the neutron
James Chadwick
suggested that atoms were small particles like billiard balls
John Dalton
size of something
magnitude
the combined total number of protons and neutrons in the nucleus of an atom
mass number
units used to measure very small things (one billionth of a metre)
nanometre
so small that it is not significant, essentially zero
negligible
having no overall charge
neutral
small particle which does not have a charge found in the nucleus of an atom
neutron
proposed that electrons orbit the nucleus in fixed orbits called shells
Niels Bohr
central part of an atom that contains protons and neutrons
nucleus
small positive particle found in the nucleus of an atom
proton
a straight line from the centre to the circumference of a circle or sphere
radius
the average mass of an atom compared to 1/12 of a carbon-12 atom
relative atomic mass
a way of writing a very large number with one number before the decimal point, multiplied by a power of 10
standard form
a physical process turning a solid directly into its gaseous state
sublimation
a way of representing elements. It consists of one or two letters
symbol