Topic 1 Electronic Structure of Atoms

The electronic configuration of an element X is …3s²3p⁵. Thus, element X is a _______ element.

• d-block

• Group 17

• Group 15

• Group 13

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NGSS.HS-PS1-1

Element X and Y are in the same short period of the Periodic Table, and have 2 and 5 electrons respectively in the outer shell. What is the most likely formula of the compound they formed?

• X₂Y₅

• X₃Y₂

• X₂Y₃

• X₅Y₂

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NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which of the following is true about the Bohr Theory?

• Lone electron revolves round the nucleus in fixed circular path known as orbitals

• Excess energy in transition between ground and excited state is released in the form of heat.

• A. Energy of orbits increases with their decreasing distance from the nucleus.

• A. Bohr’s theory is applicable to hydrogen atom only.

What is the total number of atomic orbitals in an atom with the principal quantum number n = 4?

• 30

• 20

• 16

• 23

Which of the following is NOT correct about Pauli Exclusion Principles.

• Two electrons occupying the same orbital have same set of four quantum numbers

• An orbital holds two electrons with opposite spin direction

• An atomic orbital can contains maximum of two electrons

• Each electrons have different set of four quantum numbers

What is the total number of unpaired electrons in sulphur atom?

• 1

• 2

• 3

• 4

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NGSS.HS-PS1-1

What is the valence electronic configuration of P^3-?

• ...3s²3p³

• ...3s²

• ...3s²3p⁶

• ...4s²4p³

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NGSS.HS-PS1-1

Which of the following quantum numbers describes about orientation of orbitals?

• Principal quantum number

• Spin quantum number

• Angular momentum quantum number

• Magnetic quantum number

List the four quantum numbers that describe the fourth electron in 4p subshell.

• n =4, l = 1, m_l = 0, m_s= -1/2

• n =4, l = 2, m_l = -1, m_s= +1/2

• n =4, l = 1, m_l = 0, m_s= +1/2

• n =4, l = 1, m_l = -1, m_s= -1/2

Calculate the frequency of electromagnetic radiation when an electron moves from the third shell to first shell with energy of 52.73 kJ/mol is emitted in the process.

• 1.32 x 10¹⁴ s^-1

• 8.756 x 10^-20 s^-1

• 8.756 x 10¹⁴ s^-1

• 7.95 x 10^-34 s^-1

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NGSS.HS-PS4-1

NGSS.HS-PS4-3