STRUCTURE OF ATOM Test

STRUCTURE OF ATOM

This is STRUCTURE OF ATOM Test-01 for CBSE class 12 Chemistry.. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

According to Dalton’s atomic theory

A
Atoms are indivisible
Correct
B
Atoms are made of electrons, neutrons and protons
C
Atoms are made of electrons and protons
D
Atoms are made of neutrons and protons

Cathode rays or cathode ray particles are

A
electrons
Correct
B
protons
C
muons
D
neutrons

J.J. Thomson measured the ratio of electrical charge (e) to the mass of electron (me) by using cathode ray tube and applying electrical and magnetic field perpendicular to each other as well as to the path of electrons. His experiments showed that

A
$\frac{e}{{{m_e}}}$is constant
Correct
B
$\frac{e}{{{m_e}}}$depends on electrical field
C
$\frac{e}{{{m_e}}}$depends on cathode material
D
$\frac{e}{{{m_e}}}$depends on magnetic field

Charge on the electron was determined by

A
R.A. Millikan's oil drop experiment
Correct
B
x-ray tube experiments
C
cathode ray discharge tube experiments
D
Electrical discharge carried out in the modified cathode ray tube

in the Thomson Model of Atom

A
electrons oscillate about the nucleus
B
electrons swarm like flies around nucleus
C
electrons move in circular orbits around nucleus
D
electrons are embedded in a positively charged pudding or water melon
Correct

Rutherford’s α–particle scattering experiment supported the discovery of

A
radioactivity
B
nucleus
Correct
C
proton
D
electron

Correct expression for mass number A is

A
A = number of nucleons (Z)+ number of neutrons (n)
B
A = number of protons (Z)+ number of neutrons (n)
Correct
C
A = number of protons (Z)+ number of electrons(n)
D
A = number of electrons (Z)+ number of positrons (n)

Isobars are the atoms with

A
same atomic number but different number of neutrons
B
same number of neutrons but different mass number
C
same mass number but different atomic number
Correct
D
same atomic number but different mass number

Isotopes are the atoms with

A
same atomic number but different number of electrons
B
same number of neutrons but different mass number
C
same atomic number but different mass number
Correct
D
same mass number but different atomic number

Photoelectric effect established that light

A
behaves like magnetic fields
B
behaves like rays
C
behaves like waves
D
behaves like particles
Correct

Emission spectrum of a material results from the material's (atom or molecules)

A
radiating an inverted spectrum
B
transition from excited to normal state
Correct
C
radiating a continuous spectrum
D
transition from normal to excited state

Absorption spectrum, seen as dark lines in an otherwise continuous spectrum, for a given material results from the material's (atom or molecules)

A
absorbing all wavelengths from an input of continuous spectrum
B
absorbing selected wavelengths and returning to normal ground state
C
absorbing selected wavelengths from an input of continuous spectrum
Correct
D
absorbing all wavelengths and returning to normal ground state

When an electric discharge is passed through gaseous hydrogen, the H2 molecules dissociate and the energetically excited hydrogen atoms produced emit electromagnetic radiation of discrete frequencies. The hydrogen spectrum consists of

A
several series of lines named after their discoverers
Correct
B
several lines named after their discoverers
C
a continuous spectrum that reduces to zero at large wavelengths
D
a continuous spectrum that reduces to zero at small wavelengths

Correct expression for all series of lines in the hydrogen spectrum is (n1 = 1, 2, 3... and n2 = n1 + 1, n1 +2, ... , and is the wavenumber)

A
B
C
D
Correct

According to Bohr’s theory the frequency of radiation absorbed or emitted when transition occurs between two stationary states that differ in energy by ΔE, is given by

A
ΔE = $\frac{2}{{h\nu }}$
B
ΔE =$\frac{1}{{h\nu }}$
C
ΔE =$h\nu $
Correct
D
ΔE =$2h\nu $