What is the mass number of an atom having 16 protons and 13 neutrons?

Endeleev saw trends in the physical and chemical properties of elements when he organized them by

How do scientists think that gravity affected the formation of our solar system?

An atom of lithium (li) and an atom of chlorine (cl) engage in a chemical reaction. which correctly describes the structure of the resulting chemical compound? hint: consider the class of each element. the chemical compound will have a network structure. the chemical compound will have triple bonds. the chemical compound will have a ball-and-stick structure. the chemical compound will have double bonds.