Sign in
12thPass logo
New chatPYQ LibraryDoubtsRank report
Sign in to see Recents

Your guest activity stays on this device

Sign in to save progress →
Sign in

Structure of Atom question

2019 · 12 Apr · Shift 1 · Q7
Guest · filters and generic practice availableBrowsing as a guest · PYQ filters and generic practice are available. Sign in only for personalised features and saved progress.
  1. PYQ Library
  2. /JEE Main
  3. /Chemistry
  4. /Structure of Atom
  5. /2019 · 12 Apr · Shift 1 · Q7

Structure of Atom question

2019 · 12 Apr · Shift 1 · Q7

JEE MainChemistryStructure of AtomMCQ+4 / −1
The group number, number of valence electrons, and valency of an element with atomic number 15, respectively, are:
  1. A
    16, 6 and 3
  2. B
    15, 6 and 12
  3. C
    16, 5 and 2
  4. D
    15, 5 and 3
View written solutionFree

Correct answer: D

  1. Identify the element from atomic number

Atomic number Z=15Z = 15Z=15 corresponds to phosphorus (P).

  1. Write the electronic configuration

For phosphorus: 1s2 2s2 2p6 3s2 3p31s^2\,2s^2\,2p^6\,3s^2\,3p^31s22s22p63s23p3

So, the outermost shell is the n=3n=3n=3 shell, containing: 3s23p33s^2 3p^33s23p3

Hence, the number of valence electrons is: 2+3=52 + 3 = 52+3=5

  1. Find the group number

Phosphorus belongs to the nitrogen family, which is Group 15 in the modern periodic table.

  1. Find the valency

With 5 valence electrons, phosphorus needs 3 more electrons to complete its octet. So its common valency is: 8−5=38 - 5 = 38−5=3

  1. Match with the options

We need: group number, valence electrons, valency

So the correct set is: 15, 5, 315,\ 5,\ 315, 5, 3

Checking options:

  • A: 16,6,316, 6, 316,6,3 ❌
  • B: 15,6,1215, 6, 1215,6,12 ❌
  • C: 16,5,216, 5, 216,5,2 ❌
  • D: 15,5,315, 5, 315,5,3 ✅

Therefore, the correct answer is Option D.

PreviousNext

More from Structure of Atom

  • What is the work function of the metal if the light of wavelength 4000 A∘​ generates photoelectrons of velocity 6 × 105 ms–1 from it ? (Mass of electron = 9 × 10–31 kg; Velocity of light = 3 × 108…2019 · MCQ
  • The upper stratosphere consisting of the ozone layer protects us from sun's radiation that falls in the wavelength region of -2019 · MCQ
  • If the de Broglie wavelength of the electron in nth Bohr orbit in a hydrogenic atom is equal to 1.5 π a0 (a0 is Bohr radius), then the value of n/z is -2019 · MCQ
  • Ejection of the photoelectron from metal in the photoelectric experiment can be stopped by applying 0.5 V when the radiation of 250 nm is used. The work function of the metal is :2018 · MCQ
  • The de-Broglie's wavelength of electron present in first Bohr orbit of 'H' atom is :2018 · MCQ
  • Which of the following statements is false ?2018 · MCQ
  • If the shortest wavelength in Lyman series of hydrogen atom is A, then the longest wavelength in Paschen series of He+ is :2017 · MCQ
  • The electron in the hydrogen atom undergoes transition from higher orbitals to orbital of radius 211.6 pm. This transition is associated with :2017 · MCQ