Question Text
Question 1 :
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 4 :
How many electrons are there in the L shell of chlorine atom ?
Question 5 :
Is it possible for the atom of an element to have one electron, one proton and no neutron. (Yes/No)
Question 6 :
Helium atom has a valency of zero, even after having 2 electrons in its valence shell, because
Question 8 :
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 9 :
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 10 :
The atomic number of calcium and argon are 20 and 18 respectively, but the mass number of both these elements is 40. What is the name given to such a pair of elements?