WorksheetsStructure of atom Class - IX
Total questions: 10
Worksheet time: 5mins
Who discovered the electron?
Rutherford
Chadwick
Thomson
Goldstein
What was the source of alpha particles in the Rutherford scattering experiment?
Hydrogen nucleus
Argon nucleus
Helium nucleus
None of these
What property of an element determines its chemical behavior?
Size of an element
Valency of an element
Molar mass of the element
None of these
Which scientist gave the concept of fixed energy levels around the nucleus?
Ernest Rutherford
Neils Bohr
J.J.Thomsan
None of these
What prevents an atom from being collapsed?
The nuclear forces
Movement of electrons in discrete energy levels
The electron-electron repulsions
All of these
Which of the following statements about the electron is incorrect?
It is a negatively charged particles
The mass of an electron is equal to the mass of a neutron
It is a basic constituent of all-atom
It is a constituent of cathode rays
The nucleons are
Protons and electrons
Neutrons and electrons
Protons and neutrons
None of these
In the valence shell, which of the following pairs contains duplet and octet configuration respectively?
Ne, Ar
Ca+2, O−2 ,
Li+1, N−3
Mg+2, Be+2
The correct electronic configuration of potassium is _______?
2, 8, 4
2, 8, 8, 6
2, 8, 8, 18
2, 8, 8, 1
The maximum number of electrons that a valence shell of an atom can possess is _____
18
7
32
8
