A pure substance that is made up of only one kind of atom is called an element
30 grams of radioactive isotope have passed.
Both verbs come from Olde English.
That's why everybody clearly understood their meaning until
a hundred years ago, but nobody understands them now.
"Waxing" = growing
For two weeks after the New Moon, it's growing toward Full.
First it's a waxing crescent for a week, then it's waxing gibbous.
"Waning" = shrinking
For two weeks after the Full Moon, it's shrinking toward New.
First it's waning gibbous for a week, then it's a waning crescent.
