atomic structure and periodic table revision notes

Atomic Structure and the Periodic Table

structure of an atom

- atoms are made up of sub-atomic particles called protons, neutrons, electrons

- relative mass of a proton is 1

-relative mass of a neutron is 1

-relative mass of an electron is 1/2000th 

-relative charge of a proton is +1

-relative charge of a neutron is 0

-relative charge of an electron is -1

-there is no overrall charge on an atom because the protons and electrons cancel each other out because of their relative charges, therefore making the atom neutral. 

the periodic table

- an atomic number is the number of protons, which is also the same number of electrons

- the mass number is the number of protons and neutrons in the nucleus

- an isotope is an atom that has a normal number of protons and electrons but a different number of neutrons.

- the elements in the periodic table are arranged in increasing atomic number 

- the metals are on the left 

- the non metals are on the right 

- most elements are metals

- elements are organised on their atomic numbers, electron configurations and chemical properties

- the electronic structure of an atom determines its place on the periodic table because the period number of an element is how many electron shells the atom has. the group number is how many electrons are in its outermost shell.

metals 

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