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?

First, launch the video below. you will be asked to use your knowledge of physics to predict the outcome of an experiment. then, close the video window and answer the question at right. you can watch the video again at any point. part a as in the video, we apply a charge +q to the half-shell that carries the electroscope. this time, we also apply a charge –q to the other half-shell. when we bring the two halves together, we observe that the electroscope discharges, just as in the video. what does the electroscope needle do when you separate the two half-shells again? view available hint(s) as in the video, we apply a charge + to the half-shell that carries the electroscope. this time, we also apply a charge – to the other half-shell. when we bring the two halves together, we observe that the electroscope discharges, just as in the video. what does the electroscope needle do when you separate the two half-shells again? it deflects more than it did at the end of the video. it deflects the same amount as at end of the video. it does not deflect at all. it deflects less than it did at the end of the video. submit

Consider a hydrogen atom in the ground state. what is the energy of its electron? =e= jj now consider an excited‑state hydrogen atom. what is the energy of the electron in the =5n=5 level? =e5= j

Which of these activities increases the amount of carbon in the atmosphere?