Radioactivity is 100% natural. It has been here since the first supernova star billions of years before the formation of earth about 4.5 billion years ago.
Natural is the opposite of unnatural.
Radioactivity affect the water molecules. Radioactivity makes it harmful
The way to spell the word is unnatural.
Unnatural History was created in 1983.
Unnatural Causes was created in 1967.
Unnatural Death was created in 1927.
The root word for unnatural is "natural".
What other sort of radioactivity is there?
Unnatural Causes has 236 pages.
Using unnatural color combinations. for apex :)
Radioactivity can be induced in ordinary matter by artificial transmutation.
You cannot measure radioactivity in litres