Randy Mack, age 10, of Warner, Alberta, Canada, for his question:

How do snowflakes form?

Not so long ago many experts thought that snowflakes were built from frozen droplets of misty moisture in the chilly air. We know now that this is not quite true. Hail and sleet may form from droplets of chilly water. But snowflakes form from tiny particles of vapor or gaseous water.

These water molecules afloat in the air are widely separated, and millions of them are needed to make the smallest snowflake. To get together they need a solid cc ''E of something around which to gather and gel. These cores are called nuclei, and the nucleus of a snowflake may be a fine fragment of dust, salt or soot. All water molecules are alike, and because of its odd shape the graving snowflake must arrange itself in a lacy six sided design.