Answer:
76
Explanation:
Alpha decay is one of the most basic forms of radioactive decay. It has an atomic mass of 4 and a proton number of two.
Undergoing an alpha decay will decrease the atomic mass by four and the atomic number by two.
In this particular question, we are particular about the atomic number. The atom has an atomic number of 78. So taking 2 off this gives 76
Answer: C
Explanation:
Supermassive black holes are believed to be at the center of galaxies (to provide the huge gravitational force needed to keep the galaxy together).
(4) energy and orientation
They need the energy to be able to break the original bonds, and they need the orientation to be able to bond with the new atoms