Download App

2. structure of atom — Chemistry STD 11 Science — Question

Rajasthan BoardEnglish MediumSTD 11 ScienceChemistry2. structure of atom1 Mark
MCQ
Given below are two statements : one is labelled as Assertion $A$ and the other is labelled as Reason $R$:

Assertion $A$: In the photoelectric effect, the electrons are ejected from the metal surface as soon as the beam of light of frequency greater than threshold frequency strikes the surface.

Reason $R$ : When the photon of any energy strikes an electron in the atom, transfer of energy from the photon to the electron takes place.

In the light of the above statements, choose the most appropriate answer from the options given below :

  • A
    Both $A$ and $R$ are correct but $R$ is NOT the correct explanation of $A$
  • ✓
    $A$ is correct but $R$ is not correct
  • C
    Both $A$ and $R$ are correct and $R$ is the correct explanation of $A$
  • D
    $A$ is not correct but $R$ is correct
✓

Answer

Correct option: B.
$A$ is correct but $R$ is not correct
b
There is a characteristic minimum frequency, or "threshold frequency," for each metal below which the photoelectric effect is not seen. The ejected electrons leave with a specific amount of kinetic energy at a frequency $v > v _0$ with an increase in light frequency of these electron kinetic energies also rise.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from 2. structure of atom→2. structure of atom — all question types→Chemistry STD 11 Science question papers→Rajasthan Board STD 11 Science question papers→Rajasthan Board question paper generator→

Similar questions

All reactions with chemical dissociation are
→
Cyclohexadiene contains ______  vinylic and _____ allylic hydrogen atoms ?
→
In the lewis dot structure for $\mathrm{NO}_2{ }^{-}$, total number of valence electrons around nitrogen is .......
→
A certain transition in the hydrogen spectrum from an excited state in one or more steps gives rise to a total of ten lines. Number of lines lying in visible spectrum is
→
According to Bohr's theory,

$\mathrm{E}_{\mathrm{n}}=$ Total energy, $\mathrm{K}_{\mathrm{n}}=$ Kinetic energy, $\mathrm{V}_{\mathrm{n}}=$ Potential energy , $\mathrm{r}_{\mathrm{n}}=$ Radius of $\mathrm{n}^{\text {th }}$ orbit

Match the following:

Column $I$ Column $II$
$(A)$ $\mathrm{V}_{\mathrm{n}} / \mathrm{K}_{\mathrm{n}}=$ ? $(P)$ $0$
$(B)$ If radius of $n^{\text {th }}$ orbit $\propto E_n^x, x=$ ? $(Q)$ $-1$
$(C)$ Angular momentum in lowest orbital $(R)$ $-2$
$(D)$ $\frac{1}{\mathrm{r}^{\mathrm{n}}} \propto \mathrm{Z}^{\mathrm{y}}, \mathrm{y}=$ ? $(S)$ $1$
→
$CaCO_3 + 2HCl \to CaCl_2 + CO_2 + H_2O$ ; In this chemical reaction what will be the amount of calcium chloride when $10\,g$ calcium carbonate and $400\, mL\, 0.25\, M\, HCl$ is used .............. $\mathrm{g}$
→
Choose the incorrect option about following reaction

$C{H_3} - C{H_2} - CH = C{H_2}\xrightarrow[{{H_2}{O_2}}]{{HBr}}$

→
Different hydrogen in the compound are represented by alphabets

$CH_3-CH = CH -CH_2 -CH_2 -CH(CH_3)_2$
$(A)$               $(B)\,\,\,(C)$        $(D)$    $(E)\,\,\,(F)$

arrange them in decreasing order of reactivity towards free radical substitution

→
Which of the following species has the highest electron affinity
→
The correct sequence of electron gain enthalpy of the elements listed below is

$A$. $\mathrm{Ar}$     $B$. $\mathrm{Br}$     $C. F$     $D$. $\mathrm{S}$

Choose the most appropriate from the options given below:

→