MCQ
The electronic configuration of halogens in their valence shell is:
- A$\mathrm{ns}^2$
- B$\ce{ns^2 np^6}$
- C$ns^0$
- ✓$\ce{ns^2 np^5}$

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The amount of energy required to split the double strand $DNA$ into two single strands is . . . .kcal $mol ^{-1}$.
[Given: Average energy per $H$-bond for $A - T$ base pair $=1.0 kcal mol ^{-1}, G - C$ base pair $=1.5 kcal mol ^{-1}$, and $A - U$ base pair $=1.25 kcal mol ^{-1}$. Ignore electrostatic repulsion between the phosphate groups.]
$CH_3-CH=O + C_6H_5-CH=O$ $\xrightarrow[\Delta ]{{\mathop O\limits^\Theta H(aq)}}$ $\mathop X\limits_{({C_4}{H_6}O)} $ $+$ $\mathop Y\limits_{({C_9}{H_8}O)} $
| Column $A$ | Column $B$ |
| $(i) \;\mathrm{Na}_{2} \mathrm{O}$ | $(a)$ Neutral |
| $(ii) \;\mathrm{Al}_{2} \mathrm{O}_{3}$ | $(b)$ Basic |
| $(iii)\;\mathrm{N}_{2} \mathrm{O}$ | $(c)$ Acidic |
| $(iv)\;\mathrm{Cl}_{2} \mathrm{O}_{7}$ | $(d)$ Amphoteric |
Which of the following options has all correct palrs