atomic structure
periodic table
properties of elements
The atom
electronic structure
groups
periods
group 1
group 7
Protons: mass =1, charge of + 1 in the nucleus
neutrons: mass = 1, the charge is neutral, found in the nucleus
electron: charge is negative, -1, mass is negligible, orbit in the shells
electrons are in shells
up to 2 electrons in the first shell
up to 8 electrons in the rest of the shells (GCSE)
atomic number
it's the number of protons, which is also the same amount of electrons in an atom
neon is 10
relative atomic mass number
it is the number of particles in the atom
neon is 20
1 electron in the outer shell, so it's very reactive, reactivity increases down the group, (go down, more reaction)
7 electrons in the outer shell, react by gaining electron, reactivity decreases down the group, ( go down, less reaction)
group 0
outer shells are full, chemically aren't reactive, stable (boring)
period number tells you the number of shells the element has
eg. Nitrogen is in period 2, has 2 shells of electrons
metals
non metals
properties: they are are thermal and electrical conductors, malleable (flexible), and ductile (can be pulled into a wire), generally quite dense, and solid at room temperature, high melting and boiling points
properties: thermal and electrical insulators, brittle (they can snap), can be solid, liquid, or gas, with low melting and boiling points, generally less dense than metals