<span>Because mona means 1 atom, and a compound is made up of 2 or more atoms.</span>
0.295 * 203 = 53.885
0.705 * 205 = 144.525
53.885 + 144.525 = 204.41
The relative atomic mass of Thallium is 204.41
I believe the answer is compound B may have a lower molecular weight compared to compound A.
At the same temperature, lighter particles of a compound have a higher average speeds than do heavier particles of another compound. Thus, particles of compound B are lighter than those of compound A and thus they have a higher average speed, hence evaporating faster compared to compound A.
Oxygen, fluorine and iodine are diatomic elements. Flourine is more reactive than the other two because it is the closest away to filling its outer layer of electrons and becoming stable like a noble gas.
So potassium is more reactive than lithium because the outer electron of a potassium atom is further from its nucleus than the outer electron of a lithium atom. Hope this answers the question. Have a nice day. Feel free to ask more questions.