Which of the following is a weighted average of some element

Which of the following is a weighted average of some elements having two or more different atomic masses, which are called isotopes atomic number, atomic weight The principal bond of common table salt NaCl(Sodium Chloride) is ionic covalent metallic, van der Waals.

Solution

5) Atomic Number

6) Ionic

7)Covalent

8)Substitutional Atom

9)Increases

10)Atomic packing Factor