I use letters and numbers to represent the
amounts of reactants and products involved in a
chemical change. What am I?

I am a substance present before a chemical
change. What am I?

I am the force that holds together atoms that
attach to other atoms. What am I?

I am the type of chemical reaction that releases
energy. What am I?

I produce new substances with chemical
properties that are different from those of the
original elements. What am I?

I am the substance produced in a chemical
change. What am I?

I am the type of chemical reaction that absorbs
energy. What am I?