What are isobars? Give examples.

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A: Loss of electron from hydrogen atom results in nucleus of $~1.5\times {10}^{–3} \mathrm{pm}$ size.

Reason R: Proton $\left({\mathrm{H}}^{+}\right)$ always exists in combined form.

In the light of the above statements, choose the most appropriate answer from the options given below:

Electrons in a cathode ray tube have been emitted with a velocity of $1000 {\mathrm{ms}}^{-1}$. The number of following statements which is/are true about the emitted radiation is

Given : $\mathrm{h}=6\times {10}^{-34}\mathrm{Js},{\mathrm{m}}_{\mathrm{e}}=9\times {10}^{-31} \mathrm{kg}$

(A ) The deBroglie wavelength of the electron emitted is $666.67 \mathrm{nm}$

(B ) The characteristic of electrons emitted depend upon the material of the electrodes of the cathode ray tube.

(C) The cathode rays start from cathode and move towards anode.

(D ) The nature of the emitted electrons depends on the nature of the gas present in cathode ray tube..

Match List$‐\mathrm{I}$ (Experiment performed) with List$‐\mathrm{II}$ (Phenomena discovered/associated)and select the correct option from the options given below the lists

Select the correct statements from the following :

A. Atoms of all elements are composed of two fundamental particles.
B. The mass of the electron is $9.10939 \times {10}^{-31} \mathrm{kg}$.
C. All the isotopes of a given element show same chemical properties.
D. Protons and electrons are collectively known as nucleons.
E. Dalton's atomic theory, regarded the atom as an ultimate particle of matter.

Choose the correct answer from the options given below: