Question 1 :
The number of electrons in an element X is 15 and the number of neutrons is 16. Which of the following is the correct representation of the element?
Question 2 :
Which of the following scientist identified the 'Stationary orbits' in the structure of an atom ?
Question 3 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d2b1f59b460d7261f60b.JPG' />
Find out the valency of atoms represented by the figure.
Question 4 :
State true or false: Helium atom has 2 electrons in its valence shell but its valency is not 2.
Question 5 :
The ion of an element has 3 positive charges. Mass number of the atom is 27 and the number of neutrons is 14. What is the number of electrons in the ion?
Question 6 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d2b1f59b460d7261f60a.JPG' />
Which of the above in the figures do not represent Bohr's model of an atom correctly?
Question 8 :
How many electrons are there in the L shell of chlorine atom ?
Question 9 :
Which of the following scientist identified the 'Atomic number' in the structure of an atom ?
Question 10 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d2b1f59b460d7261f60b.JPG' />
Find out the valency of atoms represented by the figure.
Question 13 :
One electron is present in the outer most shell of the atom of an element X. What would be the value of charge on the ion formed if this electron is removed from the outermost shell ?
Question 14 :
An atom with 3 protons and 4 neutrons will have a valency of
Question 15 :
Dalton’s atomic theory successfully explained:
(i) Law of conservation of mass
(ii) Law of constant composition
(iii) Law of radioactivity
(iv) Law of multiple proportion
Question 16 :
Which of the following scientist identified the 'Concept of nucleus' in the structure of an atom ?
Question 17 :
Is it possible for the atom of an element to have one electron, one proton and no neutron. (Yes/No)
Question 18 :
Helium atom has a valency of zero, even after having 2 electrons in its valence shell, because
Question 20 :
Which of the following scientist identified the 'Indivisibility of atoms' in the structure of an atom ?
Question 22 :
Which of the following scientist identified the 'Electrons' in the structure of an atom ?
Question 23 :
In the atom of an element X, 6 electrons are present in the outermost shell. If it acquires noble gas configuration by accepting requisite number of electrons, then what would be the charge on the ion so formed?
Question 25 :
In a sample of ethyl ethanoate ($CH_{3}COOC_{2}H_{5}$) the two oxygen atoms have the same number of electrons but different number of neutrons. Which of the following is the correct reason for it?
Question 26 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d2b2f59b460d7261f60c.JPG' />
Find out the valency of atoms represented by the figure.
Question 27 :
Identify the $Mg^{2+}$ ion from the figure where, n and p represent the number of neutrons and protons respectively.
Question 28 :
Which of the following element has an atom with one electron, one proton and no neutron ?
Question 29 :
The number of electrons in an element X is 15 and the number of neutrons is 16. Which of the following is the correct representation of the element?
Question 31 :
In response to a question, a student stated that in an atom, the number of protons is greater than the number of neutrons, which in turn is greater than the number of electrons. Do you agree with the statement ? (Yes/No)
Question 32 :
The ratio of the radii of hydrogen atom and its nucleus is ~ $10^{5}$. Assuming the atom and the nucleus to be spherical, what will be the ratio of their sizes ?
Question 37 :
The ratio of the radii of hydrogen atom and its nucleus is ~ $10^{5}$. Assuming the atom and the nucleus to be spherical and if atom is represented by planet earth $‘R’=6.4\times 10^{8}m$ , estimate the size of the nucleus.
Question 39 :
Atomic models have been improved over the years. Arrange the following atomic models in the order of their chronological order
(i) Rutherford’s atomic model
(ii) Thomson’s atomic model
(iii) Bohr’s atomic model
Question 40 :
The ratio of the radii of hydrogen atom and its nucleus is ~ $10^{5}$. Assuming the atom and the nucleus to be spherical and if atom is represented by planet earth $‘R’=6.4\times 10^{8}m$ , estimate the size of the nucleus.
Question 41 :
State true or false: Helium atom has 2 electrons in its valence shell but its valency is not 2.
Question 42 :
Which of the following scientist identified the 'Neutron' in the structure of an atom ?
Question 43 :
Which of the following statements about Rutherford’s model of atom are correct?
(i) considered the nucleus as positively charged
(ii) established that the $\alpha$–particles are four times as heavy as a hydrogen atom
(iii) can be compared to solar system
(iv) was in agreement with Thomson’s model
Question 44 :
Helium atom has a valency of zero, even after having 2 electrons in its valence shell, because
Question 45 :
Rutherford’s $\alpha$–particle scattering experiment showed that
(i) electrons have negative charge
(ii) the mass and positive charge of the atom is concentrated in the nucleus
(iii) neutron exists in the nucleus
(iv) most of the space in atom is empty
Which of the above statements are correct?
Question 46 :
Which of the following is true for an element?
(i) Atomic number = number of protons + number of electrons
(ii) Mass number = number of protons + number of neutrons
(iii) Atomic mass = number of protons = number of neutrons
(iv) Atomic number = number of protons = number of electrons.
Question 47 :
Rutherford’s α-particle scattering experiment led to the discovery of the ____________.
Question 48 :
Why did Rutherford select a gold foil in his $\alpha$–ray scattering experiment?
Question 49 :
The ion of an element has 3 positive charges. Mass number of the atom is 27 and the number of neutrons is 14. What is the number of electrons in the ion?
Question 50 :
Which of the following scientist identified the 'Stationary orbits' in the structure of an atom ?
