Question

Which sample of matter has a crystal structure?

(1) Hg(ℓ)
(2) H2O(ℓ)
(3) NaCl(s)
(4) CH4(g

Answer 1

3) nacl(s) is sodium chloride which crystallizes

Answer 2

Answer is: (3) NaCl(s).

1) mercury (Hg) is liquid metal.

2) water (H₂O) is liquid molecule.

3) sodim chloride (NaCl) is crystaline solid compound.

4) methane (CH₄) is gaseous molecule.

In solid, molecules are closely packed, stiff and do not changes of shape or volume. Crystal structure is ordered arrangement of atoms, ions or molecules.