Crystals can be made up of which of the following kinds of particles? 1. molecules only
2. atoms only
3. atoms, ions, or molecules
4. atoms and ions

3. atoms, ions, or molecules

Explanation:

A crystal is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.

Hope this helps!

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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