How many hydrogen atoms are in each molecule of trisilylamine?

Explanation:

The amine functional group is obtained by subsititution of one or more hydrogen atoms in the ammonia compound.

Ammonia is NH₃.

Then,

                        R'''

                         |

                 R' -  N - R''

In this case, the three subsitutuents are silyl groups. The silyl group is derived form silane and is SiH₃. So, the tcompound trisilylamine is:

                    SiH₃

                      |

          SiH₃ -  N - SiH₃

Thus, you can count 3 hydrogen atoms for every silylgroup for a total of 9 hydrogen atoms in each molecule of trisilylamine.