Question

ASSERTION :Metals like Na, K, Ca and Mg are never found in their free state in nature.
REASON :Metals are very reactive elements, so it combines with other non-metals to complete its octet.
Metals like Na, K, Ca and Mg are never found in their state in nature.
A. both assertion and reason are correct and reason is the correct explanation for assertion.
B. both assertion and reason are correct and reason is not the correct explanation for assertion.
C. assertion is correct but reason is incorrect.
D. both assertion and reason are incorrect.

Answer 1

Hint: The Na, K, Ca and Mg are alkali and alkaline earth metals. Metals tend to release the electrons. Sodium, potassium, calcium and magnesium can lose electrons easily. They react easily with the gases present in the air or with the moisture.

Complete Step by step answer: The periodic table has four blocks. Out of which s, d, and f-block contain the metals and the p-block contains metals, semimetals, and non-metals. The top left of the periodic table contains the non-metals only.
Metals tend to lose electrons. So, their reactivity is compared on the basis of electron-donating power.
On going left to right in the periodic table the reactivity of the metals decreases. On going left to right in the periodic table the electronegativity increases, so it becomes difficult to remove electrons from the metals, so the reactivity decreases.
The alkali metals are present at the top left of the periodic table and the electronegativity of the alkali metals are least so, the alkali metals are most reactive.
So, it is correct that metals like Na, K, Ca and Mg are never found in their free state in nature.
Alkali metals are so reactive that they are not found in elemental form in nature. They are found in the form of compounds. Alkali metal forms oxides in presence of oxygen or other non-metals to complete its octet.
So, it is also true that metals are very reactive elements, so it combines with other non-metals to complete its octet. Metals like Na, K, Ca and Mg are never found in their state in nature.
Therefore, option (A) both assertion and reason are correct and reason is the correct explanation for assertion, is correct.

Note: Alkali metals are sensitive or we can say very reactive to the air and water. Alkali metals are so reactive that the reaction becomes explosive. Due to the high reactivity of alkali metals towards air and moisture, they are stored in kerosene oil. The reactive of alkali metals increases down in the group. Down in the group, the electronegativity decreases so, the metal loses electrons easily so, the reactivity of the metal increases. Among alkali metals, cesium is the most reactive.