Premium Online Home Tutors

3 Tutor System

Starting just at 265/hour

Answer :

**(a) Isotopes:** Isotopes are atoms which have the same number of protons but different number of neutrons. They have same atomic number but different mass number.

Example: Carbon molecule exists as _{6}C^{12} and _{6}C^{14} but when their electronic configuration is K-2; L-4

**(b) Isobars:** Isobars are atoms which have the same mass number but different atomic number.

Example: Electronic configuration of _{20}Ca^{40}is – K-2; L-8; M-8; N- 2 and of _{18}Ar^{40} is – K-2; L-8; M-8

- What are the canal rays?
- If an atom contains one electron and one proton, will it carry any charge or not?
- On the basis of Thompson’s model of an atom, explain how the atom is neutral as a whole.
- On the basis of Rutherford’s model of an atom, which subatomic particle is present in the nucleus of an atom?
- Draw a sketch of Bohr’s model of an atom with three shells.
- What do you think would be the observation if the ?– particle scattering experiment is carried out using a foil of a metal other than gold?
- Name the three subatomic particles of an atom.
- Helium atom has an atomic mass of 4 u and two protons in its nucleus. How many neutrons does it have?
- Write the distribution of electrons in Carbon and Sodium atoms.
- If K and L shells of an atom are full, then what would be the total number of electrons in the atom?
- How will you find the valency of chlorine, sulphur and magnesium?
- 1. If the number of electrons in an atom is 8 and number of protons is also 8, then (i) What is the atomic number of the atom? and (ii) What is the charge on the atom?
- With the help of given Table, find out the mass number of oxygen and sulphur atom.
- For the symbol H, D and T, tabulate three subatomic particles found in each of them.

- NCERT solutions for class 9 maths chapter 1 Number Systems
- NCERT solutions for class 9 maths chapter 2 Polynomials
- NCERT solutions for class 9 maths chapter 3 Coordinate geometry
- NCERT solutions for class 9 maths chapter 4 Linear equations in two variables
- NCERT solutions for class 9 maths chapter 5 Introduction to Euclidean Geometry
- NCERT solutions for class 9 maths chapter 6 Lines and Angles
- NCERT solutions for class 9 maths chapter 7 Triangles
- NCERT solutions for class 9 maths chapter 8 Quadrilaterals
- NCERT solutions for class 9 maths chapter 9 Areas of parallelograms and triangles
- NCERT solutions for class 9 maths chapter 10 Circles
- NCERT solutions for class 9 maths chapter 11 Constructions
- NCERT solutions for class 9 maths chapter 12 Heron's Formula
- NCERT solutions for class 9 maths chapter 13 Surface areas and volumes
- NCERT solutions for class 9 maths chapter 14 Statistics
- NCERT solutions for class 9 maths chapter 15 Probability

- NCERT solutions for class 9 science chapter 1 Matter in our Surroundings
- NCERT solutions for class 9 science chapter 2 Is Matter Around Us Pure
- NCERT solutions for class 9 science chapter 3 Atoms and Molecules
- NCERT solutions for class 9 science chapter 4 Structure of the Atom
- NCERT solutions for class 9 science chapter 5 The Fundamental Unit of Life
- NCERT solutions for class 9 science chapter 6 Tissues and Fundamental unit of life
- NCERT solutions for class 9 science chapter 7 Diversity in Living Organisms
- NCERT solutions for class 9 science chapter 8 Motion
- NCERT solutions for class 9 science chapter 9 Force and Laws of Motion
- NCERT solutions for class 9 science chapter 10 Gravitation
- NCERT solutions for class 9 science chapter 11 Work and Energy
- NCERT solutions for class 9 science chapter 12 sound
- NCERT solutions for class 9 science chapter 13 Why do We Fall Ill
- NCERT solutions for class 9 science chapter 14 Natural Resources
- NCERT solutions for class 9 science chapter 15 Improvement in Food Resources