Atomic structure and periodic table 2 - Coggle Diagram
Atomic structure and periodic table 2
realative atomic mass
Ar= [(% of isotope 1)/ 100 x (mass of isotope 1)]- repeat for more isotopes
Definition: The weighted average mass of an atom an element compared to 1/12 the mass of a 12C atom.
Ar is calculated by multiplying the abundance (%) of each atom of an isotope by its mass number, then
adding them all up:
Isotopes are atoms of an element with the same number of protons but a different number of neutrons.
e.g. isotopes of carbon:
The group number tells us how many outer shell electrons.
The period number tells us how many shells are occupied.
Atoms are arranged in order of atomic number.
The majority of elements are metals, which are on the left. Non-metals on the right.
group numbers are columns while periods are across
Group 2 = Alkaline Earth Metals
Group 7 = Halogens
Group 1 = Alkali metals
Group 0 (8) = Noble gases. These are unreactive because they have a full outer shell so don’t gain any
extra stability from losing, gaining or sharing electrons.