If an atom gains some extra electrons so that its valence shell becomes full, what happens to the atom?

The discovery that the universe appears to be expanding led to a widely accepted theory called a.) the big bang theory b.) the doppler effect c.) hubble’s law d.) solar nebular theory e.) the seyfert theory

In a system, when potential energy decreases, then entropy also decreases. true false

Which transition by an electron will release the greatest amount of energy? oa ob oc od