STRUCTURE OF ATOM
- Name the three subatomic particles of an atom.
Ans : (i )Electrons (negatively charged)
(ii) Protons(positively charged)
(iii) Neutrons(no charge)
- What are canal rays ?
Ans : Canal rays are positively charged radiations which led to the discovery of positively charged sub- atomic particle called proton.
- If an atom contains one electron and one proton, will it carry any charge or not?
Ans : The atom will be electrically neutral as one negative charge balances one positive charge.
- On the basis of Thomson's model of an atom, explain how the atom is neutral as a whole.
Ans: According to Thomson's model of an atom-
(i) An atom consists of a positively charged sphere and the electrons are embedded in it.
(ii) The negative and positive charges are equal in magnitude. So, the atom is electrically neutral.
- On the basis of Rutherford's model of an atom, which sub-atomic particle is present in the neucleus of an atom ?
Ans :- Proton is present in the neucleus.
- Draw a sketch of Bohr's model of an atom with three shells
Ans :-
- What do you think would be the observation if the α - particle scattering experiment is carried out using a foil of a metal other than gold?
Ans :- On using any metal foil, the observations of the α - particle scattering experiment would remain the same as all atoms would hav same structure.
- What do you mean by atomic number?
Ans :- Atomic Number (Z) :- The total number of protons present in a nucleus of an atom is called its atomic number.
- What do you mean by atomic number?
Ans :- Mass number (A) :- The sum of total number of protons and neutrons present in the nucleus of an atom is called its mass number.
- How the atomic number(Z), mass number (A) and symbol of an element are represented?
Ans :-
- Write the name and symbols of the elements from the atomic number 1 to 10. Also write the number of protons and electrons also.
- Write the name and symbols of the elements from the atomic number 11 to 20. Also write the number of protons and electrons.
- Write the name and symbols of the elements from the atomic number 21 to 30. Also write the number of protons and electrons .
- Write the name and symbols of the elements from the atomic number 31 to 40. Also write the number of protons and electrons .
- What do you mean by isotopes?
Ans :- Isotopes: The atoms of same element having same atomic number but different mass numbers are called isotopes of that element.
- What are the isotopes of hydrogen?
Ans: There are three isotopes of hydrogen.
(i) Protium (ii) Deuterium (iii) Tritium
- Show the number of electrons, protons and neutrons of isotopes of hydrogen.
- What subatomic particles are different in number in isotopes of the same element?
Ans: neutrons
- What do you mean by isobars?
Ans:- Isobars : The atoms of different elements having same mass number but different atomic numbers are called isobars.
- Give example of isobars.
Ans :
- Write the symbols of elements from atomic number 1 to 20 with the representation of atomic number and mass numbers.
- Write the number of protons , electrons and neutrons of Al and Mg.
- Write the number of neutrons of O and N.
- Atomic number of an element is p and its number of neutrons is q and its symbol is A. How to represent this element symbolically?
