MCQ
Assertion (A): Hydrogen atom has only one electron in its orbit. But it produces several spectral lines.
Reason (R): There are many excited energy levels available.
  • Both A and R are true and R is the correct explanation of A.
  • B
    Both A and R are true but R is not the correct explanation of A.
  • C
    A is true but R is false.
  • D
    A is false but R is true.

Answer

Correct option: A.
Both A and R are true and R is the correct explanation of A.
(a) Both A and R are true and R is the correct explanation of A .
Explanation: A $\rightarrow$ Different lines correspond to different transitions.
B $\rightarrow$ Different transitions are due to different excited states available.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Note : In the following questions a statement of Assertion $(A)$ followed by a statement of Reason $(R)$ is given. Choose the correct option out of the choices given below each question.
Assertion $(A)$ : Among the two $O–H$ bonds in $\mathrm{H}_2\mathrm{O}$ molecule, the energy required to break the first $O – H$ bond and other $O – H $ bond is the same.
Reason $(R)$ : This is because the electronic environment around oxygen is the same even after breakage of one $O – H$ bond.
Assertion $(A)$ : Liquids tend to have maximum number of molecules at their surface.
Reason $(R)$ : Small liquid drops have spherical shape.
Direction : In the following Questions, the Assertion and Reason have been put forward. Read the statements carefully and choose the correct alternative from the following:
Assertion : Increasing order of acidity of hydrogen halides is $\ce{HF < HCl < HBr < HI}$
Reason : While comparing acids formed by the elements belonging to the same group of periodic table, $H-A$ bond strength is a more important factor in determining acidity of an acid than the polar nature of the bond.
Direction : In the following Questions, the Assertion and Reason have been put forward. Read the statements carefully and choose the correct alternative from the following:
Assertion : A solution containing a mixture of acetic acid and sodium acetate maintains a constant value of $\ce{pH}$ on addition of small amounts of acid or alkali.
Reason : A solution containing a mixture of acetic acid and sodium acetate acts as a buffer solution around $\ce{pH}\ 4.75.$
Assertion (A): Atomic mass has no unit but is expressed in amu.
Reason (R): It is the average mass of an atom taking care of the relative abundance of all its possible isotopes.
Assertion (A): Each side of a cube is measured to be 7.203 m . What is the volume of the cube to appropriate significant figure $373.7 m^3$.
Reason (R): The mass of one mole of a substance in grams is called its average atomic mass.
Direction in the following Questions, the Assertion and Reason have been put forward. Read the statements carefully and choose the correct alternative from the following:
Assertion : The density of Heavy water is higher of $11.2^\circ C.$
Reason : The density of water is higher is at $4^\circ C.$
Note : In the following question a statement of Assertion $(A)$ followed by a statement of Reason $(R)$ is given. Choose the correct option out of the choices given below:
Assertion $(A)$ : Green house effect was observed in houses used to grow plants and these are made of green glass.
Reason $(R)$ : Green house name has been given because glass houses are made of green glass.
Assertion (A): Sodium extract is made alkaline in the test of sulphur.
Reason (R): On reacting with $FeCl _3$, alkaline sodium extract, gives red colour.
Note : In the following questions a statement of Assertion $(A)$ followed by a statement of Reason $(R)$ is given. Choose the correct option out of the choices given below each question.
Assertion $(A)$ : Combustion of $16g$ of methane gives $18g$ of water.
Reason $(R)$ : In the combustion of methane, water is one of the products.