A balanced equation has an equal number of what on each side?
protons and reactions
electrons and neutrons
valencies and electrons
protons and neutrons
If you count the number of protons and neutrons on each side of this equation, you’ll see that the numbers are the same on both sides of the arrow. This means that the equation is balanced. The thorium-234 produced in this reaction is unstable, so it will undergo radioactive decay as well. The alpha particle produced in the reaction can pick up two electrons to form the element helium. This is how most of Earth’s helium formed.