Which part(s) of a telephone involves the conversion of sound waves to electrical signals?
a) the microphone
b) neither the speaker nor the microphone
c) the speaker
d) both the speaker and the microphone

What are the first two quantum numbers for the electrons located in subshell 4d? what are the first three quantum numbers for the electrons located in subshell 2s? how many electrons can be held in a sublevel l = 3? how many electrons can be held in the energy level n = 4? how many electrons in an atom can share the quantum numbers n = 4 and l = 3?