Helpful questions for exams

QUESTIONS:
1. Define:
1. Atomic number, 2. Mass number.
2. Define:
1. Electron, 2. Proton
3. Write the properties which describes the nature of cathode rays?
4. Write the main observations by RUTHERFORD from his experiment?
5. Calculate the mass and charge of one mole of electron?
6. What is photoelectric effect?

Important questions

QUESTIONS:
1. How many nodes are present in 3s orbital?
2. What is the number of orbitals in third principal shell?
3. How many electron are present in all shells with n+l=5?
4. How many shells S and P shells can accomodate?
5. In which atom the outermost electron can have the following set of quantum numbers?n=4,l=0,ml=0,ms=+1/2.
6. Give the electronic configuration of the following ions:
1. H^-
2. F^-
3. Ni²⁺
7. Define:Aufbau principle, hund's rule.
8. Discuss the shapes of p orbitals by drawing their boundry surface diagrams?
9. How many unpaired electrons are present in the ground state of;
1. P
2. Cu
3. Br
10. Draw the probability density graphs for 1s, 2s, 2p orbitals?
11. Differentiate between an orbit and orbital?

Difference between orbit and orbitals

Orbit

1. Orbit is a well-defined circular path around the nucleus in which electron revolves.
2. It represent the planar motion of an electron.
3. Orbit gives a definite path of an electron and this concept is not in accordance with the uncertainty principle.
4. All orbits are circular.
5. Orbits do not have directional characteristics.
6. An orbit can accommodate electrons equal  to 2n²   where n represents the principal quantum number.


Orbital
1. It represents the region in space around the nucleus in which the probability of finding the electron is maximum.
2. It represents the three-dimensional motion of an electron around the nucleus.
3. Orbital does not specify definite path and according to this concept, electron may be anywhere in this region. This concept is in accordance with the uncertainty principle.
4. Orbitals have different shapes. For example, s-orbital is spherical, while p-orbital is dumb bell shaped.
5. Except s-orbitals, all other orbitals have directional characteristics.
6. An orbital cannot accommodate more than two electrons.