Practice Pakistan's most useful MCQs for competitive exams

When an atom absorbs energy the lines in the spectrum will appear which are_________________?

• (A)  Brighter
• (B)  Darker
• (C)  Colourless
• (D)  Hard to locate

Answer

Submitted By :Ali Uppal

The maximum number of electron in a sub shell with ? = 3fs______________?

• (A)  6
• (B)  10
• (C)  14
• (D)  18

Answer

Submitted By :Ali Uppal

The magnetic quantum number (QN) has its values determined directly by the value of_______________?

• (A)  Principal (QN)
• (B)  Azimuthal (QN)
• (C)  Spin (QN)
• (D)  Both A & B

Answer

Submitted By :Ali Uppal

Milikan used ______________ in his atomizer?

• (A)  Milk
• (B)  Honey
• (C)  Oil
• (D)  Water

Answer

Submitted By :Ali Uppal

Electronic configuration of K is_________________?

• (A)  [Ar]4s2
• (B)  [Ar]4s1
• (C)  [Kr]5s1
• (D)  [He]2s1

Answer

Submitted By :Ali Uppal

Space around nucleus where finding probability of electrons is maximum is called ____________________?

• (A)  Orbital
• (B)  Orbit is elliptical
• (C)  subshell
• (D)  Electron cloud

Answer

Submitted By :Ali Uppal

Atom with higher atomic number produces X-rays of__________________?

• (A)  Shorter wavelength
• (B)  Larger wavelength
• (C)  X-ray not produced
• (D)  All are possible

Answer

Submitted By :Ali Uppal

When electrons collide with heavy metals than ___________ are produced?

• (A)  Beta-rays
• (B)  Alpha-rays
• (C)  X-rays
• (D)  Gamma-rays

Answer

Submitted By :Ali Uppal

Atomic orbits having same energy are called________________?

• (A)  Degenerate orbitals
• (B)  Bonding molecular orbitals
• (C)  Anti bonding molecular orbitals
• (D)  Half filled orbitals

Answer

Submitted By :Ali Uppal

The correct electronic configuration of Cu is ___________________?

• (A)  [Ar]4s1
• (B)  [Ar]4s2
• (C)  [Ar]3d104s1
• (D)  [Ar]3d94s2

Answer

Submitted By :Ali Uppal