Which of the following statements about the electron is incorrect?
1. It is a negatively charged particle
2. The mass of electron is equal to the mass of neutron
3. It is a basic constituent of all atoms
4. It is a constituent of cathode rays
Which of the following properties of atom could be explained correctly by Thomson model of atom?
1. Overall neutrality of atom
2. Spectra of hydrogen atom
3. Position of electrons, protons and neutrons in atom
4. Stability of atom
Two atoms are said to be isobars if :
1. They have same atomic number but different mass number
2. They have same number of electrons but different number of neutrons
3. They have same number of neutrons but different numbers of electrons
4. Sum of the number of protons and neutrons is the same but the number of protons is different
The number of radial nodes for 3p orbital is ______.
The number of angular nodes for 4d orbital is -
Which of the following is responsible to rule out the existence of definite paths or trajectories of electrons?
1. Pauli's exclusion principle
2. Heisenberg's uncertainty principle
3. Hund's rule of maximum multiplicity
4. Aufbau principle
Total number of orbitals associated with third shell will be _____.
Orbital angular momentum depends on _______.
2. n and l
3. n and
Chlorine exists in two isotopic forms, Cl-37 and Cl-35, but its atomic mass is 35.5. This indicates the ratio of Cl-37 and Cl-35 is approximately :
The pair of ions having the same electronic configuration is -
1. Cr3+, Fe3+
2. Fe3+, Mn2+
3. Fe3+, Co3+
4. Sc3+, Cr3+