Question 1 :
An element X has a mass number 4 and atomic number 2. Write the valency of this element?
Question 2 :
How many electrons are there in the L shell of chlorine atom ?
Question 3 :
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 4 :
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 5 :
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 6 :
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 7 :
Which of the following scientist identified the 'Concept of nucleus' in the structure of an atom ?
Question 8 :
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 9 :
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 11 :
Which of the following scientist identified the 'Electrons' in the structure of an atom ?
Question 12 :
Which of the following scientist identified the 'Atomic number' in the structure of an atom ?
Question 15 :
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 16 :
An atom with 3 protons and 4 neutrons will have a valency of
Question 17 :
Rutherford’s 'alpha ($\alpha$) particles scattering experiment’ resulted in to discovery of _______.
Question 18 :
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 19 :
Which of the following correctly represent the electronic distribution in the Mg atom?
Question 20 :
Is it possible for the atom of an element to have one electron, one proton and no neutron. (Yes/No)
Question 21 :
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 22 :
State true or false: Helium atom has 2 electrons in its valence shell but its valency is not 2.
Question 23 :
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 24 :
Calculate the number of neutrons present in the nucleus of an element X which is represented as $_{15}^{31}X$.
Question 25 :
Which of the following scientist identified the 'Stationary orbits' in the structure of an atom ?
Question 26 :
Which of the following scientist identified the 'Atomic number' in the structure of an atom ?
Question 27 :
Why did Rutherford select a gold foil in his $\alpha$–ray scattering experiment?
Question 28 :
Which of the following scientist identified the 'Concept of nucleus' in the structure of an atom ?
Question 29 :
Rutherford’s α-particle scattering experiment led to the discovery of the ____________.
Question 30 :
Identify the $Mg^{2+}$ ion from the figure where, n and p represent the number of neutrons and protons respectively.
Question 34 :
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 35 :
Which of the following is the correct electron distribution of chlorine atom ? (Atomic number of chlorine is 17).
Question 36 :
Which of the following element has an atom with one electron, one proton and no neutron ?
Question 37 : <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 38 :
Which of the following element has an atom with one electron, one proton and no neutron ?
Question 39 :
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 ?
