Question:
If an atom contains one electron and one proton, will it carry any charge or not?
Answer:
No atom will not carry any charge and remains neutral. The unit negative charge on an electron will cancel out the effect of unit positive charge on the proton. Thus the net charge on the atom is zero.
Structure of the Atom
Q 1.
Compare an electron, a proton and a neutron in respect of their relative masses and charges.
Q 2.
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?
Q 3.
Fill in the blanks :
Anode rays are also called ___________.
Q 4.
Who discovered protons?
Q 5.
Fill in the blanks :
In the three fundamental sub-atomic particles, _________ are negatively charged, _________ are positively charged and ____________ have no charges.
Q 6.
What is the relationship between an atom containing 11 protons, 11 electrons and 11 neutrons, and another atom containing 11 protons, 11 electrons and 12 neutrons ?
Q 7.
What is the absolute mass and charge of a proton ?
Q 8.
Describe briefly Thomson's model of an atom.
Q 9.
How many times is a proton heavier than an electron ?
Q 10.
On the basis of Rutherford’s model of an atom, which subatomic particle is present in the nucleus of an atom?
Q 11.
What is the maximum number of electrons which can be accommodated in the L shell of an atom
Q 12.
What is mass number?
Q 13.
What is ionization energy?
Q 14.
Give one use each of the following radioactive isotopes :
(a)Uranium-235 (b) Cobalt-60
Q 15.
State the number of electrons present in the outermost shell of the atoms of the following elements :
(i) Neon(ii)Chlorine
Q 16.
What is the maximum number of electrons an M shell of the atom can accommodate ?
Q 17.
If an atom contains one electron and one proton, will it carry any charge or not?
Q 18.
What is a neutron ? State its relative mass and charge.
Q 19.
Fill in the blanks :
Atoms are made up of __________, ___________ and __________.
Q 20.
Write a short note on Nucleus.
Q 21.
Fill in the blanks :
______ are atoms of the same element, which have same number of protons but different mass numbers.
Q 22.
Name the radioactive isotope which is used in the treatment of cancer.
Q 23.
Fill in the blanks :
Atomic number is equal to _____________.
Q 24.
Fill in the blanks :
The maximum number of electrons that can be accommodated in L-shell are _______.
Q 25.
What is the maximum number of electrons that can go into the N shell of an atom ?
Q 26.
State one use of radioactive isotopes in medicine.
Q 27.
How does an electron differ from a neutron ?
Q 28.
State one use of radioactive isotopes in industry.
Q 29.
What name is given to those isotopes which have unstable nuclei and emit various types of radiations ?
Q 30.
Fill in the blanks :
The fundamental particle not present in hydrogen atom is __________.
Q 31.
Fill in the blanks :
Nucleons are __________ and ___________.
Q 32.
Fill in the blanks :
The mass number of an atom is equal to the number of ________ in its nucleus.
Q 33.
What is the maximum number of electrons which can be accommodated in the K shell of an atom
Q 34.
Which shell of an atom can accommodate a maximum of
(a) 8 electrons?
Q 35.
What is a proton ? How does it differ from a neutron ?
Q 36.
(a) Describe Bohr's model of the atom. How did Neils Bohr explain the stability of atom ?
(b) An element has an atomic number of 11 and its mass number is 23. What is the arrangement of electrons in the shells ? State nuclear composition of an atom of the element.
Q 37.
What name is given to those atoms which contain the same number of protons and electrons but different number of neutrons ?
Q 38.
(a)What are valence electrons ? Where are valence electrons situated in an atom ?
(b)What is the number of valence electrons in the atoms of an element having atomic number 13 ? Name the Valency shell of this atom.
Q 39.
Name the fundamental particle not present in the nucleus of hydrogen atom
Q 40.
What were the observations of Rutherford's ?-scattering experiment?
Q 41.
What were the important features of atomic model based on Rutherford's scattering experiment?
Q 42.
Fill in the blanks :
________ rays are negatively charged.
Q 43.
Fill in the blanks :
The _________ of an atom is dense, small in size and is positively charged.
Q 44.
Fill in the blanks :
Co-60 a radio isotope is used in treatment of __________.
Q 45.
Name the particles which actually determine the mass of an atom.
Q 46.
What do you understand by the term 'electronic configuration' of an element ? Write down the electron configuration of oxygen (At. No. = 8).
Q 47.
State whether the following statement is true or false :
Radioactive isotope of iodine is used for making the medicine called tincture iodine.
Q 48.
Fill in the following blanks in respect of an atom of an element :
No.of
protons | No.of
neutrons | Mass number | Atomic
number | No.of
electrons | Valency |
|---|
| 11 | 12 | ........ | ....... | ........ | ......... |
Q 49.
What valencies will be shown by the elements A, B, C, D and E having atomic numbers 2, 4, 8, 10, and 13 respectively.
Q 50.
Given that the percentage abundance of the isotope
Ne, is 90% and that of the isotope
Ne, is 10%,calculate the average atomic mass of neon.
