Question

Differentiate btw. solution , suspension and colloids​

Answer 1

Answer:

A solution is always transparent, light passes through with no scattering from solute particles which are molecule in size. The solution is homogeneous and does not settle out. ... A colloid is intermediate between asolution and a suspension. While asuspension will separate out a colloidwill not.

Answer 2

Theorem.

If for some positive integer n, 2n-1 is prime, then so is n.

Proof.

Let r and s be positive integers, then the polynomial xrs-1 is xs-1 times xs(r-1) + xs(r-2) + ... + xs + 1. So if n is composite (say r.s with 1<s<n), then 2n-1 is also composite (because it is divisible by 2s-1).

Notice that we can say more: suppose n>1. Since x-1 divides xn-1, for the latter to be prime the former must be one. This gives the following.

Corollary.

Let a and n be integers greater than one. If an-1 is prime, then a is 2 and n is prime.

Usually the first step in factoring numbers of the forms an-1 (where a and n are positive integers) is to factor the polynomial xn-1. In this proof we just used the most basic of such factorization rules, see for some others.