What substance is composed of one type of atom

Any substance that contains only one type of atom is referred to as an element.Elements are the "building blocks" of everything. Each element only contains one type of atom. If substances carry more than one type of atom, then they are compounds.

what does the table look like

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

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