what is a silvery white metal with an average of 178.5 amu. And when you add 7 protons what element is it

Answer 1

The silvery white metal with an average atomic mass of approximately 178.5 amu is likely tantalum (Ta), which has an atomic mass of about 180.95 amu.

If you add 7 protons to tantalum (which has an atomic number of 73), you would have an element with an atomic number of 80. The element with atomic number 80 is mercury (Hg).

So, to summarize:

• The silvery white metal is tantalum (Ta).
• Adding 7 protons gives you mercury (Hg).