Among the second period elements the actual ionization enthalpies are in the order `Li lt B lt Be lt C lt O lt N lt F lt Ne`.
Explain why
(i) Be has higher ∆i H than B
(ii) O has lower ∆i H than N and F?

Among the second period elements the actual ionisation enthalpies are in the order LiltBltBeltCltOltNltFltNe . Explain why (a) Be has higher Delta_(i)H than B and (b) O has lower Delta_(i)H than N and F ?

Among the third period elements, the actual ionization enthalpies are in the order Na lt AI lt Mg lt SI lt S lt Plt CI lt Ar . Explain why: (i) Mg has higher Delta_(i)H than AI . (ii) S has lower Delta_(i)H than P and CI .

With reference to 1^(st) IP which are correct. (a) Li lt C (b) O lt N (c ) Be lt N lt Ne

If P, Q, R and S are elements of 3rd period of p-block in modern periodic table, among these one element is metal and rest are non-metals and their order of electronegativity is given as: P lt Q lt R lt S In which of the following linkage release of H^+ is relatively more easier?

Identify the null sets among the following F = {x : x in N , 5 lt x lt 6. }

This question concerna a symmetrical lens shown, along with its two focal points. It is made of plastice with n=1.2 and has focal length f. Four different regions are shown: Here, A. -oox lt -f B. -f lt x lt 0 C. 0 lt x lt f D. f lt x lt oo Q. If incident rays are converging, then in which region does the image appear?

Which one of the following indicates the correct order of atomic size? (1). C gt F gt Ne" "(2) Be lt C lt F lt Ne (3). Be gt C gt F" "(4) F gt Ne gt Be gt C

If z =x +iy lies in the third quadrant then (barz)/(z) also lies in third quadrant if (i) x gt y gt 0 (ii) x lt y lt 0 (iii) y lt x lt 0 (iv) y gt x gt 0

This question concerns a symmetrical lens shown, along with its two focal points. It is made of plastic with n=1.2 and has focal length f. Four different regions are shown: A. -oo lt x lt -f B. -f lt x lt 0 C. 0 lt x lt f D. f lt x lt oo A second lens is now placed adjacent to the first in contact with it. The new lens is concave, with a focal length f=-3f . In what region does the focal length of the two-lens system lie? Treat the lenses as thin.

The number of 7 digit integers abcdefg, where a lt b lt c lt d gt e gt f gt g such that a, b, c, d, e, f, g in {1,2,3,…..,9} . Are