18. when is an atom unlikely to react and form chemical bonds? 19. what is the order of the types of nuclear radiation from lowest to highest energy? 20. which statement is false? rewrite it so that it is true. a. fusion involves the combination of two smaller atoms into a larger atom. b. fission involves the splitting of an atom into smaller atoms. c. fission and fusion are two processes that release very little amounts of energy. 21. what naturally occurring radioisotope is used as the fuel for a nuclear reactor? 22. magnesium oxide is a binary ionic compound. from its formula, mgo, how do you know that mg is the metal? 23. on the periodic table, there are two numbers in the block for the element potassium, k: 19 and 39.098. what are the names of the numbers and what do they measure?