Radioactive elements include all those elements whose nuclei contain more than
1.
83 amu
83 nucleons
83 neutrons
83 protons

Which best describes how johannes kepler developed his laws of planetary motion

An atom of sodium-23 (atomic number = 11) has a positive charge of +1. give this information, how many electrons does it have? how many proteins and neutrons does this atom have

Many ionic compounds and a few highly polar covalent compounds are because they completely ionize in water to create a solution filled with charged ions that can conduct an electric current.