Group 18 are stable because thier outermost shell ocuppied with full of electrons and its chemically inert
In comparison see it is very easy in goolge
Use blue litmus paper. This is an indicator that can safely determine whether it is a base or an acid by changing color in response to the substance. This color indicates whether it is an acid or a base. Refer to the pH scale to see if the substance is basic or acidic.
Answer: The correct answer is C.
Explanation: Frictional force is the contact force which resists the motion of one surface on another.
Mathematically,

where,
f = frictional force
= Coefficient of friction
N = normal force acting on a body
We need to find the ratio of force of sliding friction ( which is a type of frictional force) and the normal force acting on an object. This will be equal to coefficient of friction.
