- Therefore they share the smaechemical properties

- Different physical properties(Density, melting point and boilingpoint)

- Find the proton number of the atom

- Find out the numbers of electrons fromthere. (number of protons = number ofelectrons)

- Arrange the electrons in shells. Electronsoccupy the shell closest to the nucleusfirst

- Electrons only start occupying a newshell when the previous one has beenoccupied

- Electrons found in theoutermost occupied shell of anatom

- Outermost shell refers to theshell which is furthest from thenucleus

- Nature of elements can bedetermined by the number ofvalence elctrons

- Gain electrons

- Lose electron

- Molecules of compounds

- Molecules of elements

- Hold a negative charge

- mass of 1/1836

- 1/2000 the mass of a proton

- Number of electron andneutron = mass number

- No charge

- mass of 1

- Holds a positive charge

- mass of 1

- Number of protons = atomic number