The nucleus contains: protons and electrons
protons and neutrons
electrons
protons, neutron, and electons

Check the correct box to describe the periodic trends in electronegativity. electronegativity across a period: decreases. increases. electronegativity down a group: decreases. increases.

May someone me with these science questions

The valence of aluminum is +3, and the valence of the chlorine is -1. the formula fir the aluminum chloride is correctly written as