I believe it is covalent bonds not 100% sure
There are three ways that scientists have proved that these sub-atomic particles exist. They are direct observation, indirect observation or inferred presence and predictions from theory or conjecture. Scientists in the 1800's were able to infer a lot about the sub-atomic world from chemistry.
Explanation:
H is hydrogen and Na is sodium.
Hydrogen is the first element of the periodic table. Its atomic no is 1. Its atomic weight is 1.008. Its electronic configuration is 1s¹.
Na is hydrogen. It lies at 3rd period and 1st group. Its atomic number is 11. Its atomic weight is 22.989769 u. Its electronic configuration is 2,8,1.