3
MCQ (Single Correct Answer)
The probability density plots of 1s and 2s orbitals are given in figure.
The density of dots in a region represents the probability density of finding electrons in the region.
On the basis of above diagram which of the following statements is incorrect?
A
$1 s$ and $2 s$ orbitals are spherical in shape
B
The probability of finding the electron is maximum near the nucleus
C
The probability of finding the electron at a given distance is equal in all directions
D
The probability density of electrons for $2 s$ orbital decreases uniformly as distance from the nucleus increases
4
MCQ (Single Correct Answer)
Which of the following statement is not correct about the characteristics of cathode rays?
A
They start from the cathode and move towards the anode
B
They travel in straight line in the absence of an external electrical or magnetic field
C
Characteristics of cathode rays do not depend upon the material of electrodes in cathode ray tube
D
Characteristics of cathode rays depend upon the nature of gas present in the cathode ray tube
5
MCQ (Single Correct Answer)
Which of the following statements about the electron is incorrect?
A
It is a negatively charged particle
B
The mass of electron is equal to the mass of neutron
C
It is a basic constituent of all atoms
D
It is a constituent of cathode rays
6
MCQ (Single Correct Answer)
Which of the following properties of atom could be explained correctly by Thomson model of atom?
A
Overall neutrality of atom
B
Spectra of hydrogen atom
C
Position of electrons, protons and neutrons in atom
D
Stability of atom
7
MCQ (Single Correct Answer)
Two atoms are said to be isobars if
A
they have same atomic number but different mass number
B
they have same number of electrons but different number of neutrons
C
they have same number of neutrons but different number of electrons
D
sum of the number of protons and neutrons is same but the number of protons is different