Download App

3. Classification of elements and periodicity in properties — Chemistry STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceChemistry3. Classification of elements and periodicity in properties1 Mark
MCQ
Assertion : First ionization energy for nitrogen is lower than oxygen.
Reason : Across a period effective nuclear charge decreases.
  • A
    If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
  • B
    If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
  • C
    If the Assertion is correct but Reason is incorrect.
  • ✓
    If both the Assertion and Reason are incorrect.
✓

Answer

Correct option: D.
If both the Assertion and Reason are incorrect.
d
The ionisation energy of $N$ is more than that of $O$ because $N$ has exactly half filled valence $p$ orbital. $_7N$ $1s^2\, 2s^2\,p^3$       $_8O$ $1s^2\, 2s^2\,p^4$ 

The nuclear charge increases across a period.

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 3. Classification of elements and periodicity in properties→3. Classification of elements and periodicity in properties — all question types→Chemistry STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

A solution of optically active $1$ -phenylethanol racemizes in acidified aqueous  medium. It is due to
→
What is the debroglie wavelength of electron, in hydrogen atom, moving in an orbit having maximum magnetic quantum no. $ = +2$ $\mathop {\rm{A}}\limits^{\rm{o}} $
→
Which of the following is used for making optical instruments:
→
The electronic structure of molecule $O{F_2}$ is a hybrid of
→
$n-$ hexane $\xrightarrow{{catalyst}}$ benzene

catalyst is

→
Among $I-A$ elements which is the only non-metal?
→
Which of the following product is formed when $SiF_4$ reacts with water ?
→
Nitration takes place at the which position of the given compound ?
→
The correct statement($s$) about the following reaction sequence is(are)

(image)

($A$) $R$ is steam volatile

($B$) $Q$ gives dark violet coloration with $1 \%$ aqueous $FeCl_3$ solution

($C$) $S$ gives yellow precipitate with $2, 4$-dinitrophenylhydrazine

($D$) $S$ gives dark violet coloration with $1 \%$ aqueous $FeCl_3$ solution

→
Among the following species which two have trigonal pyramidal shape ?

$(I)$ $NI_3$                    $(II)$ $I_3^-$   

$(III)$ $SO_3^{-2}$         $(IV)$ $NO_3^-$

→