The most probable answer is: (a) <span>The black pot emits heat at a faster rate than the silver pot. It means the black pot conducts heat at a higher rate than the silver pot, that's why it cooled off faster. It also means that the silver pot retains heat better and is more of an insulator.</span>
Hydrogen gas(H2) has a molar mass of 2 g. Molar mass of a substance is defined as the mass of 1 mole of that substance. And by 1 mole it is meant a collection of 6.022*10^23 particles of that substance.
So number of moles of H2 are 0.5 in this case. And thus it means there are (6.022*10^23)*0.5 particles( here they are molecules) in 1g of H2.
B) 6
one above one below and 2 on the left and right sides
Mechanical twinning occurs in metals having body center cubic and hexagonal closed packed structures. Twinning is said to occur when a portion of a crystal takes up an orientation that is related to the orientation of the untwinned lattice in a definite symmetrical manner.
