Question:
State the number of electrons present in the outermost shell of the atoms of the following elements :
(i) Neon(ii)Chlorine
Structure of the Atom
Q 1.
If A = 23 and Z = 11 for Na atom, how many protons, electrons and neutrons present in Na atom?
Q 2.
Who discovered electrons?
Q 3.
What were the important features of atomic model based on Rutherford's scattering experiment?
Q 4.
Who discovered protons?
Q 5.
Fill in the blanks :
Rutherford's scattering experiment is related to to the size of ____________.
Q 6.
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 7.
Write a short note on Nucleus.
Q 8.
Fill in the blanks :
_______ are atoms having the same mass number but different atomic numbers.
Q 9.
How many times is a proton heavier than an electron ?
Q 10.
What is the maximum number of electrons which can be accommodated in the L shell of an atom
Q 11.
What are cathode rays?
Q 12.
Name the scientist who discovered electron.
Q 13.
What is a proton ? How does it differ from a neutron ?
Q 14.
(a) Describe the Rutherford's model of an atom. State one drawback of Rutherford's model of the atom.
(b) The mass number of an element is 23 and it contains 11 electrons. What is the number of protons and neutrons in it ? What is the atomic number of the element ?
Q 15.
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.
Q 16.
Fill in the blanks :
In the three fundamental sub-atomic particles, _________ are negatively charged, _________ are positively charged and ____________ have no charges.
Q 17.
If an atom contains one electron and one proton, will it carry any charge or not?
Q 18.
State one use of radioactive isotopes in medicine.
Q 19.
Describe briefly Thomson's model of an atom.
Q 20.
On the basis of Rutherford’s model of an atom, which subatomic particle is present in the nucleus of an atom?
Q 21.
What were the observations of Rutherford's ?-scattering experiment?
Q 22.
What is Atomic Number? Who coined this term?
Q 23.
What is the maximum number of electrons that can go into the N shell of an atom ?
Q 24.
What is the maximum number of electrons an M shell of the atom can accommodate ?
Q 25.
What is the maximum number of electrons which can be accommodated in the K shell of an atom
Q 26.
Draw a sketch of Bohr’s model of an atom with three shells.
Q 27.
Fill in the blanks :
________ rays are negatively charged.
Q 28.
Fill in the blanks :
Nucleons are __________ and ___________.
Q 29.
Which part of an atom was discovered by Rutherford's alpha particle scattering experiment ?
Q 30.
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 | Symbol |
|---|
| 11 | 12 | ........ | ....... | ........ | ......... |
Q 31.
What name is given to the pair of atoms such as
N and
N ?
Q 32.
What are isobars ? Explain with an example.
Q 33.
Complete the following table.
| Particle | Electron | Proton | Neutron |
|---|
| (i) Symbol | __ | __ | __ |
| (ii) Nature | __ | __ | __ |
| (iii) Relative Charge | __ | __ | __ |
| (iv) Absolute Charge | __ | __ | __ |
| (v) Relative Mass | __ | __ | __ |
| (vi) Absolute Mass | __ | __ | __ |
Q 34.
Fill in the blanks :
Atoms are made up of __________, ___________ and __________.
Q 35.
Fill in the blanks :
Anode rays are also called ___________.
Q 36.
Fill in the blanks :
Atomic number is equal to _____________.
Q 37.
Name the radioactive isotope which is used in the treatment of cancer.
Q 38.
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 39.
(a) What are radioactive isotopes ? Give two examples of radioactive isotopes.
(b)Give any two uses of radioactive isotopes.
(c)An element Z contains two naturally occurring isotopes
Z and
Z. If the average atomic mass of this element be 35.5 u, calculate the percentage of two isotopes.
Q 40.
What are the properties of anode rays?
Q 41.
Fill in the blanks :
__________ electrons are located in the outermost shell of an atom.
Q 42.
What is the electronic configuration of a hydrogen atom
Q 43.
How does a proton differ from an electron ?
Q 44.
What name is given to those atoms which contain the same number of protons and electrons but different number of neutrons ?
Q 45.
Complete the following statements :
(a) Magnesium has 2 valence electrons in the......... shell.
(b)The valency of nitrogen in N2 molecule is........
(c)Isotopes have different mass numbers because their nuclei contain different number of........
(d) Some boron atoms have mass number 10 and some have mass number 11. These boron atoms with different mass numbers are called............
Q 46.
What are canal rays?
Q 47.
Name the particles which actually determine the mass of an atom.
Q 48.
What is the absolute mass and charge of an electron ?
Q 49.
What is the absolute mass and charge of a proton ?
Q 50.
State the location of electrons, protons and neutrons in an atom.
