MCQ
In the sixth period, the orbitals being filled are :-
- A$5s, 5p, 5d$
- B$6s, 6p, 6s, 6f$
- C$6s, 5f, 6d, 6p$
- ✓$6s, 4f, 5d, 6p$
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

| $\Delta H \,(kJ/mol)$ | |
| $\frac 12 A \rightarrow B$ | $+150$ |
| $3B \rightarrow 2C + D$ | $-125$ |
| $E + A \rightarrow 2D$ | $+350$ |
For $B + D \rightarrow E + 2C, \Delta H$ will be ............. $\mathrm{kJ/mol}$