Explanation:
Given that,
Two resistors of resistance 6 ohm and 3 ohm are connected in series and then in parallel.
For series combination,

For parallel combination,

When 6 ohm and 3 ohm are in series,

When 6 ohm and 3 ohm are in paralle,

So, the equivalent resistance in series combination is 9 ohms and in parallel combination it is 2 ohms.
Answer : A) nucleons
Protons and neutrons are sometimes collectively called nucleons because they both are inside the nucleus of an atom.
Answer:
Classification of the Elements. These three groups are: metals, nonmetals, and inert gases.
Explanation: