Electrically neutral atoms of the same element must

A. contain the same number of neutrons

B. have the same mass number

C. contain the same number of protons

D. have equal numbers of protons and neutrons

Astring vibrates with a frequency of 10 hz. why can't a person hear the sound waves produced by the vibrating string, no matter how large the amplitude of the waves? out! this is homework and due tomorrow! you so much!