The answer is Conduction: the process of heat is directly transmitted through a substance when there is a difference in temperature.
Gasses because they are comperssible (plato)
Answer:

is the no. of electrons
Explanation:
Given:
- quantity of charge transferred,

<u>No. of electrons in the given amount of charge:</u>
As we have charge on one electron 
so,


is the no. of electrons
- Now if each water molecules donates one electron:
Then we require
molecules.
<u>Now the no. of moles in this many molecules:</u>

where
Avogadro No.


- We have molecular mass of water as M=18 g/mol.
<u>So, the mass of water in the obtained moles:</u>

where:
m = mass in gram


first we make a U turn and travel towards home in t = 20 s
so the distance of home from initial position is


Now after picking up the book we travel back with speed 20 m/s
so again after t = 20 s the displacement is given as

so the net displacement is given as


so it will be displaced by total displacement 200 m