34 solutions available
Question 1Compare the properties of electrons, protons and neutrons.
Question 2What are the limitations of J.J. Thomson's model of the atom?
Question 3What are the limitations of Rutherford's model of the atom?
Question 4Describe Bohr's model of the atom.
Question 5Compare all the proposed models of an atom given in this chapter.
Question 6Summarise the rules for writing of distribution of electrons in various shells for the first eighteen elements.
Question 7Define valency by taking examples of silicon and oxygen.
Question 8Explain with examples(i) Atomic number,(ii) Mass number,(iii) Isotopes and(iv) Isobars.Give any two uses of isotopes.
Question 9Na+ has completely filled K and L shells. Explain.
Question 10If the bromine atom is available in the form of, say, two isotopes 3579Br (49.7%) and 3581Br (50.3%), calculate the average atomic mass of...
Question 11The average atomic mass of a sample of element X is 16.2 u. What are the percentages of isotopes 816X and 818X in the sample?
Question 12If Z=3, what would be the valency of the element? Also, name the element.
Question 13Composition of the nuclei of two atomic species, X and Y, are given as under XYProtons =66Neutrons =68Give the mass numbers of X and Y....
Question 14For the following statements, write T for True and F for False.(a) J.J. Thomson proposed that the nucleus of an atom contains only...
Question 15Rutherford's alpha–particle scattering experiment was responsible for the discovery ofAtomic nucleusElectronProtonNeutron
Question 16Isotopes of an element haveThe same physical propertiesDifferent chemical propertiesDifferent number of neutronsDifferent atomic numbers
Question 17Number of valence electrons in Cl- ion are1681718
Question 18Which one of the following is a correct electronic configuration of Sodium?2, 88, 2, 12, 1, 82, 8, 1
Question 19Complete the following table.Atomic NumberMass NumberNumber of NeutronsNumber of ProtonsNumber of ElectronsName of the Atomic Species9 10...
Question 1What are the canal rays?
Question 2If an atom contains one electron and one proton, will it carry any charge or not?
Question 1On the basis of Thompson's model of an atom, explain how the atom is neutral as a whole.
Question 2On the basis of Rutherford's model of an atom, which subatomic particle is present in the nucleus of an atom?
Question 3Draw a sketch of Bohr's model of an atom with three shells.
Question 4What do you think would be the observation if the ∝–particle scattering experiment is carried out using a foil of a metal other than gold?
Question 1Name the three subatomic particles of an atom.
Question 2Helium atom has an atomic mass of 4 u and two protons in its nucleus. How many neutrons does it have?
Question 1Write the distribution of electrons in carbon and sodium atoms.
Question 2If K and L shells of an atom are full, then what would be the total number of electrons in the atom?
Question 1How will you find the valency of chlorine, sulphur and magnesium?
Question 1If the number of electrons in an atom is 8 and the number of protons is also 8, then(i) What is the atomic number of the atom? and(ii) What...
Question 2With the help of the given table, find out the mass number of oxygen and sulphur atom.Composition of Atoms of the First Eighteen Elements...
Question 1For the symbol H, D and T, tabulate three subatomic particles found in each of them.
Question 2Write the electronic configuration of any one pair of isotopes and isobars.