From the following nuclei, choose the isotopes and isobars :
(i) 8p + 8n , (ii) 8p +9n , (iii)18p + 22n , (iv)20p + 20n

(a) The element helium has 2 electrons in its valence shell but its valency is not 2. Explain (b) Choose the isotopes from the following nuclie: (i)8p+8n,(ii) 8p+9n,(iii) 18p +22n ,(iv)20p+20n

Identify the isotopes and isobars from the following list of atoms with given number of protons and neutrons. A:8p+9nB:8p+8nC:18p+22nD:20p+20n .

Simplify the following using the formula a^m xx a^n = a^(m+n) : p^5 xx p^8 .

Let P(n) = 1 + 3 + 5 + ... + (2n - 1) = 3 + n^2 , then which of the following is true? (i) P (3) is correct (ii) P (2) is correct (iii) P(m) rArr p(m+1) (iv) P(m) cancel(rArr) P(m+1)

Find the value of n if (i) ( n + 1) ! = 20 ( n-1 ) ! ( ii) 1/( 8!) + 1/( 9 !) = n/( 10 !)

Solve : (11m - 12n + 3p) - (9m + 7n - 8p)

If n(P) = 20, n(Q) = 18 and n(Puu Q) = 27 , then n(P - Q) =

Arrange the following in the increasing order of their basicities. (I) p- Toluidine (II) N,N- Dimethyl-p-toluidine (III) p- Nitroaniline (IV) Aniline.

Find d for an A.P. if (i) t_(10) =20, t_(9) = 18 (ii) t_(n) = 7, t_(n-1) = 10

Let P(n) :n^(2) lt 2^(n), n gt 1 , then the smallest positive integer for which P(n) is true? (i) 2 (ii) 3 (iii) 4 (iv) 5