Choose (E) Element (C)Compound (M) Mixture for the following1. Cannot be decomposed by chemical means2. Has a definite composition3. Pure substance composed of identical atoms4. Can be separated by physical means5. Can be separated by chemical means6. Magnesium7. water8. air9. salt water solution10. can be heterogeneous11. ammonia (NH3)12. composition may vary13a13b13c13d

1) Element

2) Compound

3) Element

4) Mixture

5) Compound

6) Element

7) Compound

8) Mixture

9) Mixture

10) Mixture

11) Compound

12) Mixture

Explanation:

A compound refers to a combination of two or more atoms of the same or different elements Eg NH3.

A mixture refers to any combination of substances which do not chemically reavt together and are separable by physical methods.

An element refers to a substance that contains only one type of atom.

each  column  of the  table  is called a group. elements in a group share similar properties. groups are  read  from  top  to  bottom. metal. metalloid. nonmetal. solid. liquid. gas. fe. hg. o.  2. 3. 4. 5. 6. 7. 8. 9.  2. beryllium. 9.012. 4.  sodium. 22.990.  11. 3.  magnesium. 24.305.  12.  potassium. 39.098.  19. 4.  calcium. 40.078.  20. i guess  i