Please help me with these Radioactive Decay Problems ASAP! I need help

Ionic compounds are made of ions, and yet the overall charge of an ionic compound is neutral. why?

Increasing the substrate concentration in an enzymatic reaction could overcome which of the following? a) the need for a coenzymeb) allosteric inhibitionc) competitive inhibitiond) insufficient cofactors

To calculate percent by mass, use the equation below: calculate the percent by mass of each element. %n = % %h = % %o = %