Tag: study of matter

Questions Related to study of matter

An atom of an element loses two electrons to form an ion. The quantum numbers of the electrons lost are $n = 4 :and :l = 0$. If another atom of the same element loses one more electron to form an ion, the quantum numbers (Principle and Azimuthal) of this electron lost are ________.

evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. 1,2

  2. 3,2

  3. 3,4

  4. 4,5

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Correct Option: B
Explanation:

Quantum number $n = 4,:l = 0$ corresponds to 4s electrons. When two 4s electrons are lost, a dipositive ion is formed. The configuration of the element could be $3s^23p^64s^2 :or :3s^23p^63d^{1-10} 4s^2$. Since the atom of the same element can lose one more electron, it should be the 'd' block element. 


Iron is the element showing +2 and +3 oxidation states, the configuration could be $3s^23p^63d^64s^2$. The $3^{rd}$ electron lost has quantum numbers $n = 3$, $ l=2$.$Fe^{+3}$  is smaller than $Fe^{+2}$ ion. This is because effective nuclear force of attraction in $Fe^{+3}$  is more than that in $Fe^{+2}$.

Assuming that the number of maximum permissible shells is 5, elements would be there in the periodic table is:

evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. 52

  2. 54

  3. 55

  4. 51

Show answer
Correct Option: B
Explanation:

According to Aufbau principle the order of filling of orbitals is:
$1s\ 2s\ 2p\ 3s\ 3p\ 4s\ 3d\ 4p\ 5s\ 4d\ 5p\ 6s\ 4f\ 5d\ 6p$
For maximum shell of 5, electrons will be filled upto 5p orbital as (each period)
$(1s^2)(2s^22p^6)(3s^23p^6)(4s^23d^{ 10 }4p^6)(5s^24d^{ 10 }5p^6)$
$2+8+8+18+18=54$
Therefore maximum number of atoms would be 54.
option B is correct.