Which of the following would not have the same number of valence electrons as the others?

oxygen
carbon
sulfur
selenium

Match the following items. 1. high-intensity bundle of energy being emitted from some decaying nuclei gamma ray 2. particle radiating from the nucleus of some atoms beta particle 3. negative particle identical to an electron but radiating from a decaying nucleus alpha particle

If a polyatomic ionic compound has gained two hydrogen ions, then how does its name begin?

Which of these conditions most likely produces an unstable isotope?