Which of these substances are molecules? 1. h2o 2. nacl 3. n2 4. o2 question 12 options: 3 and 4 all of them 1 and 2 none of them

The answer is; All of them

A molecule is a stable chemical unit (with neutral charge) of atoms chemically bonded together (these bonds can be covalent, metallic, ionic, and etcetera). The molecule can, therefore, be of an element (contain atoms of the same element – in this case, N2 and O2) or a compound (atoms of different elements- in this case, H2O and NaCl).

a:

by the combination of an unlimited number of elements

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.

that's it!

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