The way he looks at you. He wants to give to you. Real love is about giving, not taking. This is why parents typically love their children more than their children love them. You would think it would be the opposite. From birth through our teenage years and sometimes beyond!
He finds random excuses to contact you He finds the most random reasons to reach out to you. He sends you funny cat memes on Messenger. He calls to tell you he found his lucky purple sock. Maybe he sends you pictures of himself:
Problem solving using the half-life of a radioisotope or radioactive emission data to work out the half-life of a radioactive isotope. What is the half-life of radioactive isotopes? What is a radionuclide decay curve?