Question

valency of popular and important elements​

Answer 1

A lithium atom has one outer shell electron, so it's usual valence is +1, but it can lose the electron and have a valence of -1. This is a table of the valences or oxidation states of the elements.

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Table of Valences of the Elements 6.

NUMBER =76

SYMBOL =Os

ELEMENT =Osmium

VALENCE =8, 7, 6, 5, 4, 3, 2, 1, 0, -2

*******IMPORTANT ELEMENTS*******

The acronym CHNOPS, which stands for carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur, represents the six most important chemical elementswhose covalent combinations make up most biological molecules on Earth. All of these elements are nonmetals. 

Answer 2

Answer:

A lithium atom has one outer shell electron, so it's usual valence is +1, but it can lose the electron and have a valence of -1. This is a table of the valences or oxidation states of the elements.

...

Table of Valences of the Elements 6.

NUMBER 76

SYMBOL Os

ELEMENT Osmium

VALENCE 8, 7, 6, 5, 4, 3, 2, 1, 0, -2