What is the correct order of occurrence ($\%$ by weight) in air of $Ne, Ar$ and $Kr$?

The structure of a mixed oxide is cubic close packed $(ccp)$. The cubic unit cell of the mixed oxide is composed of oxide ions. One-fourth of the tetrahedral voids are occupied by divalent metal $A$ and the octahedral voids are occupied by a monovalent metal $B$. The formula of the oxide is

Which one of the following halogens liberates oxygen,when passed through hot concentrated $KOH$ solution?

An oxide of an element is a gas and dissolves in water to give an acidic solution. The element belongs to

Bordeaux mixture was discovered by

For all values of $a$ and $b$,the line $(a+2b)x + (a-b)y + (a+5b) = 0$ passes through a fixed point. Find that point.