Questions

Iteration means doing something again and again, repeatedly,... 

Hence, looping is a process of repeating a method and so it is similar in meaning to Iteration.

Microwaves are high-frequency signals in the 300 MHz to 300 GHz range. This is in contrast to radio signals, which are typically broadcast in all directions. Radio signals operate in the 3 Hz to 300 MHz range.

Microwave signals are used for both satellite and ground-based communications.

The letter 'P' sounds same as the vegetable 'PEA'.

Hence P is an alphabet which is a vegetable.

Jatindra Nath Das, also known as Jatin Das, was a revolutionary and Independence activist. He embraced death in Lahore jail after fasting for 64 days in 1929 at the age of 24 yrs.

Central Processing Unit (CPU) is the brain of any computer system.

When atoms react they do so in order to reach the lowest energy, which is the most stable. The electrons orbitals will overlap in the way that reduces the energy the most. Orbitals of similar energy will produce the greatest stabilisation.The answer you gave isn't the whole story, it depends what species is reacting with what. The effective nuclear charge on the atom will affect the energy of the valance electrons.

Hence, the reactivity of an atom arises from the existence of unpaired electrons in the valence shell.