Timothy Foley, age 13, of Kingston, On t., Canada, for his question:

HOW DID ATOMS COME INTO BEING?

The original atoms of the universe are hydrogens, and nobody knows for certain how they came into being. However, we know that these smallest of atoms can be used to build bigger ones. For example, this happens in the fiery furnaces of the starry sun. There the original hydrogen atoms are used to build larger atoms of helium.

The basic atom is a package of particles charged with energy to make the whole thing work just so. The protons in its tight fisted nucleus have a positive charge, just strong enough to hold on to an equal number of negative electrons. The character of an atom depends on the number of protons in its nucleus. When an atom loses or gains a proton, it becomes an atom of something else.

We have a list of 900 or so different atoms, each having one more proton than the one before it. The smallest is the hydrogen atom, with only one proton in its nucleus. The next is helium with two protons. These two elements are not very abundant on the earth, but they account for 99$ of all the matter in the universe. Vast clouds of hydrogen gas spread among the stars, and the stars themselves are mostly hydrogen and helium.

Our sun was formed from a great cloud of hydrogen gas, and those hydrogen atoms provide the fuel for its nuclear furnace. Its fiery heart is hot enough to remodel the nuclei of these atoms and build new ones. In this process of nuclear fusion, the nuclei of hydrogen atoms fuse to build helium nuclei. And fragments of surplus material are converted into dynamic energy called nuclear radiation.

Hydrogen seems to be the basic building material of the universe, and helium atoms come into being as the stars consume their hydrogen fuel. Helium is the ashes of the nuclear furnace, matter that does not burn in the temperature of a young star. But stars grow older and conditions change. Then hydrogen atoms are used to build metals and other larger atoms

We may not know how the original hydrogen atoms came into being. But certainly the stars use their hydrogen atoms to build larger and still larger atoms. Some of these atoms are unstable. Then a reverse process of radioactivity is used to change them. For example, big heavy atoms of uranium break down into a series of smaller and smaller atoms. This process finally ends as atoms of lead.