MCQ
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : The arrangement of metals in order of decreasing reactivities is called reactivity series.
Reason : Metals at the top of series are very reactive and metals at the bottom are least reactive.
  • A
    Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
  • Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
  • C
    $A$ is true, but $R$ is false.
  • D
    $A$ is false, but $R$ is true.

Answer

Correct option: B.
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
Metals at the top of the series are very reactive and therefore, they do not occur free in nature. The metals at the bottom of the series are least reactive and therefore, they normally occur free in nature.

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

For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : The movement of water and dissolved salts in xylem is always upwards.
Reason : The upward movement of water is due to low pressure created by transpiration.
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Food materials are often packed in air tight container.
Reason : Oxidation, resulting in rancidity, is prevented.
Assertion (A): Colour of copper sulphate solution changes when an iron nail is kept immersed in it.
Reason (R): The colour of copper sulphate solution changes when iron nail is kept immersed in it due to the decomposition reaction taking place between iron and copper leading to formation of iron sulphate.
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Genes present in every cell of an organism control the traits of the organisms.
Reason : Gene is specific segment of $\text{DNA}$ occupying specific position on a chromosome.
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Spore formation is found in unicellular organisms only.
Reason : Rhizopus and Mucor reproduce by spore formation method.

Assertion (A): The magnitude of the magnetic field at a point on the axis of a current-carrying solenoid is inversely proportional to the current flowing through the solenoid. 
Reason (R): The magnitude of the magnetic field at a point on the axis of a current-carrying solenoid is directly proportional to the number of turns per unit length of a solenoid. 

In each of the following questions, a statement of Assertion is given by the corresponding statement of Reason. Of the statements, mark the correct answer as :
Assertion : Menstruation is the regular discharge of blood from the thick uterine lining.
Reason : Menstruation occurs when egg is fertilized by sperm.
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Food waste can be converted to compost by burying in a pit dug into ground and used as manure.
Reason : Non $-$ biodegradable wastes like fruit and vegetable peels, tea leaves, broken glass jar are ideal for composting.
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Down the group, atomic radius increases.
Reason : Electrons are added in new shell.

Assertion (A): Corrosion of iron is commonly known as rusting
Reason (R): Corrosion of iron occurs in presence of water and air.