Assertion: In an electrochemical cell anode and cathode are respectively negative and positive electrodes.
Reason: At anode oxidation takes place and at cathode reduction takes place.

Assertion and Reason both are correct statements and reason is the correct explanation for assertion.

The correct answer is: 1. Assertion and Reason both are correct statements, and the reason is the correct explanation for the assertion.
Assertion: In an electrochemical cell, anode and cathode are respectively negative and positive electrodes.
Reason: At the anode, oxidation takes place, and at the cathode, reduction takes place.
Both the assertion and the reason are correct statements, and the reason provides the correct explanation for the assertion.
In an electrochemical cell, the anode is the electrode where oxidation occurs. During oxidation, electrons are lost from the anode, leading to the formation of positive ions in the solution. These positive ions then move towards the cathode.
The cathode is the electrode where reduction occurs. At the cathode, positive ions from the solution gain electrons and undergo reduction, forming neutral atoms or molecules.
Since electrons flow from the anode to the cathode, the anode becomes negatively charged (due to the loss of electrons), and the cathode becomes positively charged (due to the gain of electrons).
Therefore, the reason correctly explains why the anode is negative and the cathode is positive in an electrochemical cell, making option 1 the correct answer.