What is RU87?

Answer 1

Usually refers to the chemical element rubidium (Rb), frequently confused with the Ruthenium (Ru), which is an element used for dating long periods of time, because the 87 rubidium isotope, transforms into Strontium 87

Answer 2

RU87 is a code designation for specific chemicals or materials. Without more context, it is difficult to provide a specific answer.