Question 1 :
Bohr modified the ___________ by adding that the electrons move in orbits of fixed size and energy.

Question 2 :
Alpha-particles that come closer to nuclei in Rutherford's alpha particle scattering experiment:

Question 3 :
In 1911, __________ came to the conclusion that the atom had a dense nucleus because most of the particles shot straight through, but some of the particles were deflected due to the dense nucleus of the gold atoms.

Question 4 :
Choose the correct option.<br/>In the outermost shell of any atom :

Question 5 :
Nucleus of an element has nine protons. Its valency would be:&#160;&#160;<br/>

Question 6 :
Match the atomic numbers 4, 14, 8, 15, and 19 with&#160;a metal of valency 1.

Question 7 :
Which of the following particles is not deflected in the magnetic field?

Question 8 :
Statement I: Radiation and radioisotopes can have beneficialuses<br>Because<br>Statement II: Radioisotopes and radiation can be used for radiodating, radiotracers, and food preservation<br>

Question 10 :
(a) As long as an electron revolves in a particular orbit, the electron does not lose its energy. Therefore, these orbits are called stationary orbits and the electrons are said to be in stationary energy states.<br>(b) Each orbit or shell is associated with a definite amount of energy. Hence these are also called energy levels.<br>(c) An electron jumps from a lower energy level to a higher energy level, by absorbing energy. It jumps from a higher energy level to a lower energy level, by emitting energy in the form of electromagnetic radiation.<br>(d) Electrons move around the nucleus in specified circular paths called orbits or shells or energy levels and are designated as K, L, M, N shells respectively.<br>Arrange the above postulates of Bohr's theory in a correct sequence.

Question 11 :
The oxidation state of Barium in $Ba({ H }_{ 2 }{ PO }_{ 2 }{ ) }_{ 2 }$&#160; is:

Question 13 :
Multiple Answer Question&#160;<br/>According to Bohr, when electron jumps from one shell to another:

Question 14 :
Statement 1: The value of Avogadro's constant is $6.022\times {10}^{23}$<br/>Statement 2: Mole is the ratio of number of atoms present in the substance to the Avogadro number.<br/>Now choose the correct option :