Answer:
solve example number 2 ....
Explanation:
solve examole number 2 .....
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!
Explanation:
The atoms of one element differs from the atoms of other elements in terms of the number of protons they contain. This is often taken as the atomic number of such an atom.
- The number of proton is the best indicator of the atom one is dealing with.
- Based on this number, elements are categorized into distinct columns and rows on the periodic table.
- The atomic number is the number of protons or positively charge particles in the atom.
II.
It is possible to change the identity of an atom. This is only possible by altering the atomic number of the atom.
Only nuclear reactions have this capability.
When an atom undergoes nuclear reaction that involves change in number of protons, transmutation occurs and a new atom forms.
Answer: The molar mass of each gas
Explanation:
Mole fraction is the ratio of moles of that component to the total moles of solution. Moles of solute is the ratio of given mass to the molar mass.

Suppose if there are three gases A, B and C.
a) 
b) 
c) 
moles of solute =
Thus if mass of each gas is known , we must know the molar mass of each gas to know the moles of each gas.