hemistry 2 Exam- revision.
Looking more closely at the atom
Structure of the atom
. Atoms have a central nucleus made of protons and neutrons.
. Around the centre nucleus are electrons.
. Protons have a charge of +1; electrons have a charge of -1; neutrons are neutral (a charge of 0).
. Atoms always have the same number of protons as electrons. This is why they are always neutral.
. The number of protons an atom has is called its atomic (Proton) number.
Where do electrons go?
. Electrons occupy particular energy levels (or shells).
. Electrons always occupy the lowest possible energy level avalible (the shell closes…