A system of 4 electrons, 18 protons, and 4 neutrons has a net charge of?

+ 14

Explanation:

18 protons make a positive 18 charge (+18)

4 electrons make a negative 4 charge (-4)

both combined give + 18 - 4 = + 14

The four neutrons don't carry net charge, so the addition of the electrons doesn' affect the net charge found above which still gives + 14.

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.