In the unit cell of galena, six square faces of equal size each form 90 degree angles with every adjacent face. what type of crystal system is this?

tetragonal
hexagonal
triclinic
cubic

Answer : The correct option is, Cubic.

Explanation :

As there are seven types of crystal systems which are cubic, tetragonal, orthorhombic, monoclinic, triclinic, rhombohedral and hexagonal.

A unit cell is characterized by the axial length (a, b and c) and axial angle parameters which decide the size and shape of the unit cell.

In tetragonal crystal system, and

In hexagonal crystal system, and

In triclinic crystal system, and

In cubic crystal system, and

Hence, the correct option is, Cubic.

the answer is na (sodium)

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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