The number main-group elements'valance electrons can be determined on the periodic table

Valance electrons can be determined by Group on the periodic table

Group 1 - 1 valence electron.

Group 2 - 2 valance electrons.

Group 13 - 3 valence electrons.

Group 14 - 4 valance electrons.

Group 15 - 5 valence electrons.

Group 16 - 6 valence electrons.

Group 17 - 7 valence electrons.

Group 18 - 8 valence electrons.

Result: No of valence electron can be determined by the group no. of the element.

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

explanation: