How old is the earth in millions of years

Explain why pure hydrogen cyanide does not conduct electricity, but become a conductor when it is dissolved in water? (at room temp, pure hcn exists as a volatile liquid)

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

Which two scientific disciplines are bridged by pharmaceutical drugs? chemistry and forensics chemistry and medicine biology and forensics biology and criminology