what’s the difference between an atom & an ion?
ion is a changed particle, atom is an unchanged particle
does carbon form ions?
no, it could either lose/gain 4 electrons
does neon form ions?
no, it already has a full outer shell
why does sodium chloride (NaCl) have a lower melting point than magnesium oxide (MgO)?
- Mg 2+ and O 2- have a greater charge than Na+ and Cl-
- therefore the electrostatic attraction is stronger
- requires more energy to overcome
why can ionic compounds be brittle?
- when hit with force, the layers of ions can slide over each other
- this can cause ions with same charge to end up next to each other
- causes repulsion, lattice will break at this point
are solid ionic compounds soluble?
no, because the ions aren’t free to move due to the strong electrostatic attraction (in a fixed place)
what’s the relative mass of a proton?
1
what’s the relative mass of a neutron?
1
what’s the relative mass of an electron?
0.001
what’s meant by the term ‘relative atomic mass’?
the average mass of atoms of an element, taking into account their abundance
what do periods mean?
the amount of electron shells
what do groups mean?
the amount of electrons in its outer shell
which row are periods?
horizontal rows
which rows are groups?
vertical rows
