When a radioactive isotope releases an alpha particle, the atomic number of the atom is decreased by four.
So, the correct answer is B.
Hope this helps,
Davinia.
Answer:

Explanation:
Hello.
In this case, given the heat of fusion of THF to be 8.5 kJ/mol and freezing at -108.5 °C, for the required mass of 5.9 g, we can compute the entropy as:

Whereas n accounts for the moles which are computed below:

Thus, the entropy turns out:

Best regards.
Answer:
G<0, spontanteous
H<0, from equation
S>0, gas to solid
Explanation:
The small bags of silica gel you often see in a new shoe box are placed there to control humidity. Despite its name, silica gel is a solid. It is a chemically inert, highly porous, amorphous form of SiO2. Water vapor readily adsorbs onto the surface of silica gel, so it acts as a desiccant. Despite not knowing mechanistic details of the adsorption of water onto silica gel, from the information provided, you should be able to make an educated guess about the thermodynamic characteristics of the process. Predict the signs of ΔG, ΔH, and ΔS.
G<0, spontanteous
H<0, from equation
S>0, gas to solid