planetary model, atomic mass and atomic number

Question

according to the planetary model, an electron emits light when it

 

a.  moves from an energy level farther from the nucleus to an energy level closer to the nucleus

b.  moves from an energy level closer to the nucleus to any energy level farther from the nucleus

c.  orbits between energy levels

d.  none of these

 

2.  how many protons does a nucleus element contain if the atomic number is 8 and the atomic mass is 15.99?

 

           I have 15.99 minus 8 equals 7.99

 

3.  the atomic   spectrum of an element is

 

a.  made up of all frequencis of visible light

b.  produced by energized neurons

c.  unique for that element

d.  all of these

 

thanks

 

 

Answer 1

1) If energy is added AKA absorbed, this means that it goes from a lower energy level to a higher one, or from an inner shell to an outer one. In this case, light is emitted so its the opposite- goes to a lower level (more inner). If its going more inner that means it is going closer to the nucleus= A.

 

2) You are right except these numbers have to be integer values so its 8 protons.

 

3) It is all of them