Refraction is the bending of light (it also happens with sound, water and other waves) as it passes from one transparent substance into another. This bending by refraction makes it possible for us to have lenses, magnifying glasses, prisms and rainbows. Even our eyes depend upon this bending of light. Hope this helps!
Answer:
ELEMENTS MIXTURE
Elements are made up of one kind of atoms. Mixtures are made up of two or more kinds of Compounds .
Elements cannot be broken down into simpler substances by any physical or chemical method. The various constituents are seperated by simple physical means
Answer: The coefficient is 3.645
The exponent is 1
There are 4 significant digits
The rightmost significant figure is 5
Explanation:
Scientific notation is defined as the representation of expressing the numbers that are too big or too small and are represented in the decimal form with one digit before the decimal point times 10 raise to the power.
For example : 5000 is written as 
According to avogadro's law, 1 mole of every gas contains avogadro's number
of particles, occupy 22.4 L at STP and weighs equal to its molecular mass.
131.29 g of Xe occupy = 22.4 L at STP.
Thus 213.62 g of
occupy =
at STP.
Scientific notation = 
The coefficient is 3.645
The exponent is 1
There are 4 significant digits
The rightmost significant figure is 5