Question 1 :
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 2 :
Which of the following scientist identified the 'Neutron' in the structure of an atom ?
Question 3 :
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 4 :
Which of the following correctly represent the electronic distribution in the Mg atom?
Question 5 :
Which of the following scientist identified the 'Canal rays' in the structure of an atom ?
Question 6 :
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 7 :
Which of the following scientist identified the 'Electrons' in the structure of an atom ?
Question 8 :
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 9 :
Identify the $Mg^{2+}$ ion from the figure where, n and p represent the number of neutrons and protons respectively.
Question 10 :
Calculate the number of neutrons present in the nucleus of an element X which is represented as $_{15}^{31}X$.
Question 12 : <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 13 :
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 14 :
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 15 :
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 16 :
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 17 :
State true or false: In an atom the number of protons and electrons is always equal.
Question 18 :
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 19 :
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 21 :
Neon and chlorine have atomic numbers 10 and 17 respectively. Their valencies will be ______ and _______ respectively.
Question 22 :
Rutherford’s α-particle scattering experiment led to the discovery of the ____________.
Question 23 :
Which of the following scientist identified the 'Indivisibility of atoms' in the structure of an atom ?
Question 24 :
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 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 26 :
Which of the following scientist identified the 'Electrons' in the structure of an atom ?
Question 27 :
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 29 :
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 31 : <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 33 :
An atom with 3 protons and 4 neutrons will have a valency of
Question 34 :
Which of the following scientist identified the 'Atomic number' in the structure of an atom ?
Question 35 :
Which of the following scientist identified the 'Atomic number' in the structure of an atom ?
Question 36 :
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 37 :
Why did Rutherford select a gold foil in his $\alpha$–ray scattering experiment?
Question 38 :
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 40 :
Which of the following scientist identified the 'Neutron' in the structure of an atom ?
Question 41 :
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 42 :
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 43 :
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 44 :
Which of the following scientist identified the 'Stationary orbits' in the structure of an atom ?
Question 48 :
Which of the following element has an atom with one electron, one proton and no neutron ?
Question 50 :
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?
