Rene' Mather, age 15, of Victoria, B.C., Canada, for her question:

What is the composition of the sun's atmosphere?

More than 60 of the elements of the earth have been identified in the sun, and to some degree. These atoms are present in the transparent solar atmosphere. The principal gases in the sun's atmosphere, however, are hydrogen and calcium.

For a while, experts were baffled by certain elements high in the solar atmosphere. Later, these were found to be atoms of iron and nickel which had been stripped of their outer shells of electrons. Oxygen and sodium are also present. Helium, which is rare in the sun, seems to be more plentiful in the sun's filmy envelope of seething gases.