It is common to associate groups of elements which have similar arrangement of electrons in the atoms of the elements.

• Groups 1 and 2 and Groups 13 - 18 are known as the Main Group Elements.
• Groups 3 - 12 are known as the Transition Elements.
• Hydrogen is a Main Group element.

1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18
																1 H	2 He
3 Li	4 Be											5 B	6 C	7 N	8 O	9 F	10 Ne
11 Na	12 Mg											13 Al	14 Si	15 P	16 S	17 Cl	18 Ar
19 K	20 Ca	21 Sc	22  Ti	23  V	24 Cr	25 Mn	26 Fe	27 Co	28 Ni	29 Cu	30 Zn	31 Ga	32 Ge	33 As	34 Se	35 Br	36 Kr
37 Rb	38 Sr	39 Y	40 Zr	41 Nb	42 Mo	43 Tc	44 Ru	45 Rh	46 Pd	47 Ag	48 Cd	49 In	50 Sn	51 Sb	52 Te	53 I	54 Xe