If atomic number of an element is 25 and .its atomic mass is 55, then its nucleus contains:
A. 25 protons and 30 neutrons
B. 55 protons
C. 30 protons and 25 neutrons
D. 55 neutrons
Answer:A
If atomic number of an element is 25 and .its atomic mass is 55, then its nucleus contains:
A. 25 protons and 30 neutrons B. 55 protons C. 30 protons and 25 neutrons D. 55 neutrons