Question

Waht is the meaning of valency and and the valencies of 18 groups

Answer 1

A measurement of the power of an atom to combine with others, by the number of hydrogen atoms it can combine with or take the place of is called valency

Normally, 0, but the noble gas in KrF2 , RnF2, XeF2 and XeF(1+) and KrF(1+) salts, it is 2, In XeF4, XeO2, XeOF2, and XeF3(1+) salts, it is 4. In XeF6, XeOF4, XeO2F2, RnO3, and XeF5(1+) and XeF8(2-) salts it is 6. And in XeO4 and XeO2F4 it is 8. There is an interesting compound Xe2(1+)Sb4F21(1-) with valence 1/2 and an Xe-Xe bond.

Answer 2

Answer:

The etymology of the words valence (plural valences) and valency (plural valencies) traces back to 1425, meaning "extract, preparation", from Latin valentia "strength, capacity", from the earlier valor "worth, value", and the chemical meaning referring to the "combining power of an element" is recorded from 1884