Answer:
A
Explanation:
Isotopes are atoms of the same element with the same number of protons and electrons but different numbers of neutrons.
Isotopes can also be defined as atoms of the same element with the same atomic number but different mass numbers e.g isotopes of chlorine, oxygen and so on.Oxygen for instance has three isotopes with the same atomic number,8 and different mass numbers,16,17 and 18.
Answer : The heat required is, 1904 calories.
Explanation :
The process involved in this problem are :

The expression used will be:
![\Delta H=m\times \Delta H_{fusion}+[m\times c_{p,l}\times (T_{final}-T_{initial})]](https://tex.z-dn.net/?f=%5CDelta%20H%3Dm%5Ctimes%20%5CDelta%20H_%7Bfusion%7D%2B%5Bm%5Ctimes%20c_%7Bp%2Cl%7D%5Ctimes%20%28T_%7Bfinal%7D-T_%7Binitial%7D%29%5D)
where,
m = mass of ice = 17 g
= specific heat of liquid water = 
= enthalpy change for fusion = 
Now put all the given values in the above expression, we get:
![\Delta H=17g\times 80.0cal/g+[17g\times 1cal/g^oC\times (32.0-0)^oC]](https://tex.z-dn.net/?f=%5CDelta%20H%3D17g%5Ctimes%2080.0cal%2Fg%2B%5B17g%5Ctimes%201cal%2Fg%5EoC%5Ctimes%20%2832.0-0%29%5EoC%5D)

Therefore, the heat required is, 1904 calories.
False because they can turn back to their original form a chemical change would be like burning paper it can’t be changed back to it’s original offer it’s burnt
The atoms or molecules attain enough kinetic energy to overcome any intermolecular attractions they have. Since there are no longer any attractive forces between the particles, they are free to drift away into space. The same sort of thing hapens in ordinary evaporation, but only at the surface.