D, you can't see ultraviolet rays and other similar frequency waves with the naked eye.
Density
=mass÷volume
=19.67÷5.90
=3.33 g/ml
The appropriate answer is D. volatility. Volatility refers to the susceptibility of liquids to vaporize. Perfume is liquid when applied but because of volatility, it has a tendency to vaporize and so it will convert to a gas and diffuse across the room. The process by which a liquid changes to a vapor is called evaporation.
Answer:
It is called tempering. Its tensile strength may reduce but it will become more rigid and hard to break compared to the original metal.
Explanation:
( Source : Quora )