Ответ:

Na- ²³Na, 11, 23

¹¹

Mg - 12, 12, 12, 24

Mg -12, 25, 13

Cl - 35, 17, 35

Cl - ³⁷Cl, 17, 20, 17, 37

¹⁷

Fe - ⁵⁶ Fe, 26, 56, 26

²⁶

Cu - 29, 34, 29, 63

Cu - ⁶⁵Cu, 65, 29, 36

²⁹