`6^12C` , `8^40Ar` , `6^14C` , `20^40Ca`
Find the isotopes and isobars pairs among them. Justify it?

Symbols (not real symbols) of some atoms are given. 8^17P , 18^40Q , 16^8P , 20^40R Find the atomic number and mass number of these elements.

Find the value of ""^6C_2

Symbols (not real symbols) of some atoms are given. 8^17P , 18^40Q , 8^16P , 20^40R Which among these, are isotopic pairs?

In the figure, BC =14, /_B = 40^@ , /_C = 50^@ Find the area of triangle ABC.

What is the sum of first 40 natural numbers? [(1640 , 820 , 410 , 205)] ii) Whât is the sum of first 40 terms of the arithmetic sequences 6,12,18,.....? iii) The sum of first 40 terms of an arithmetic sequence with common difference 6 , is '5120 .' Write down the aigebraic form of this sequence.

Symbols (not real symbols) of some.atoms are given. underset(8) overset (17) \P ,underset(18) overset (40) \ Q, underset(8) overset (16) \R a) Find the atomic number and mass number of these elements. b) Which among these are isotopic pairs? c) Draw the Bohr model of atom Q.

Symbols (not real symbols) of some atoms are given underset(8) overset (17) \ P , underset(18) overset (40)\Q , underset(8) overset (16) \ R , underset(20) overset (40)\S a) Find the atomic number and mass number of these elements . b) Which among these are isotopic pairs? c) Draw the Bohr model of atom Q

In triangle A B C, /_A=40 ^circ, B C=8 cm Find the circum diameter of the triangle. [sin '40=0.64]'

A,B, C, D and E five elements (These symbols are not real? underset (7) overset (17)\ A ,underset(6) overset(16)\B, underset(7) overset(16 )\C, underset (8) overset (16) \D, underset(8) overset(17) \E a) Find out which among them are isotopes. b) Find out the number of neutrons in each one.

Analyse the given samples and answer the questions. a. NH_3 b. 50g CaCO_3 (N - 14, H - 1, Ca - 40, O - 16, C - 12) i) Find the GMM of NH_3 ii) Find the number of atoms in sample b.