Question 1 :
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 2 :
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 3 :
Which of the following scientist identified the 'Canal rays' in the structure of an atom ?
Question 4 :
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 5 :
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 6 :
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 7 : <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 8 :
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 9 :
Which of the following scientist identified the 'Electrons' in the structure of an atom ?
Question 10 :
In the Thomson’s model of atom, which of the following statments are correct?
(i) the mass of the atom is assumed to be uniformaly distributed over the atom
(ii) the positive charge is assumed to be uniformaly distributed over the atom
(iii) the electrons are uniformaly distributed in the positively charged sphere
(iv) the electrons attract each other to stabilise the atom.
Question 11 :
Helium atom has a valency of zero, even after having 2 electrons in its valence shell, because
Question 12 :
How many electrons are there in the L shell of chlorine atom ?
Question 13 :
Which of the following correctly represent the electronic distribution in the Mg atom?
Question 14 :
In the Thomson’s model of atom, which of the following statments are correct?
(i) the mass of the atom is assumed to be uniformaly distributed over the atom
(ii) the positive charge is assumed to be uniformaly distributed over the atom
(iii) the electrons are uniformaly distributed in the positively charged sphere
(iv) the electrons attract each other to stabilise the atom.
Question 15 :
Why did Rutherford select a gold foil in his $\alpha$–ray scattering experiment?
Question 17 :
Which of the following scientist identified the 'Atomic number' in the structure of an atom ?
Question 18 :
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 19 :
Rutherford’s α-particle scattering experiment led to the discovery of the ____________.
Question 20 :
In the Gold foil experiment of Geiger and Marsden, that paved the way for Rutherford’s model of an atom, ~ 1.00% of the $\alpha$-particles were found to deflect at angles > $50^{\circ}$. If one mole of $\alpha$-particles were bombarded on the gold foil, compute the number of $\alpha$-particles that would deflect at angles less than $50^{\circ}$.
Question 22 :
Is it possible for the atom of an element to have one electron, one proton and no neutron. (Yes/No)
Question 23 :
An element X has a mass number 4 and atomic number 2. Write the valency of this element?
Question 24 :
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 26 :
An atom with 3 protons and 4 neutrons will have a valency of
Question 27 :
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 28 :
Which of the following scientist identified the 'Indivisibility of atoms' in the structure of an atom ?
Question 29 :
Calculate the number of neutrons present in the nucleus of an element X which is represented as $_{15}^{31}X$.
Question 31 :
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 32 :
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 33 :
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 34 :
Rutherford’s 'alpha ($\alpha$) particles scattering experiment’ resulted in to discovery of _______.
Question 35 :
State true or false: Helium atom has 2 electrons in its valence shell but its valency is not 2.
Question 36 :
Which of the following scientist identified the 'Canal rays' in the structure of an atom ?
Question 37 :
Which of the following scientist identified the 'Stationary orbits' in the structure of an atom ?
Question 38 :
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 39 :
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 40 : <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 41 :
An element X has a mass number 4 and atomic number 2. Write the valency of this element?
Question 42 :
Calculate the number of neutrons present in the nucleus of an element X which is represented as $_{15}^{31}X$.
Question 44 :
One electron is present in the outer most shell of the atom of an element X. What would be the nature of charge on the ion formed if this electron is removed from the outermost shell ?
Question 45 :
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 46 : <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 47 :
State true or false: In an atom the number of protons and electrons is always equal.
Question 49 :
Helium atom has a valency of zero, even after having 2 electrons in its valence shell, because
Question 50 :
Which of the following scientist identified the 'Concept of nucleus' in the structure of an atom ?
