- AOil drop experiment.
- BPlanck's quantum theory.
- Cx-ray scattering experiment.
- DExperiments on conduction of gases.
Explanation:
Bohr proposed his atomic model based on planck's quantum theory.
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| List $I$ (Spectral Series for Hyddrogen) | List $II$ (Spectral Region/Higher Energy State) |
| $A$. Lyman | $I$. Infrared region |
| $B$. Balmer | $II$. $UV$ region |
| $C$. Paschen | $III$. Infrared region |
| $D$. Pfund | $IV$. Visible region |
Choose the correct answer from the options given below :-
$(A)$ The decreasing order of atomic radii of group $13$ elements is $\mathrm{Tl}>\mathrm{In}>\mathrm{Ga}>\mathrm{Al}>\mathrm{B}$.
$(B)$ Down the group $13$ electronegativity decreases from top to bottom.
$(C)$ $\mathrm{Al}$ dissolves in dil. $\mathrm{HCl}$ and liberate $\mathrm{H}_2$ but conc. $\mathrm{HNO}_3$ renders Al passive by forming a protective oxide layer on the surface.
$(D)$ All elements of group 13 exhibits highly stable +1 oxidation state.
$(E)$ Hybridisation of $\mathrm{Al}$ in $\left[\mathrm{Al}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}$ ion is $\mathrm{sp}^3 \mathrm{~d}^2$.
Choose the correct answer from the options given below:
