Answer:
d. may melt if heat is transferred to it from hot mantle rock rising up into the crust.
Explanation:
Hot, solid rock in the Earth's crust is a solid outer region of the Earth, Underneath the Earth Structure lies the mantle which is composed of solid rocks especially granite and basalt. The mantle is very hot and may melt if heat is transferred to it from hot mantle rock rising up into the crust therefore forming a molten magma. It may even be hotter (and not cooler as it was stated in the option A which makes it the wrong answer) than the surface lava because of the pressure of the overlying rock. As such, This effect is seen when a volcanic eruption occurs.
The answer would be, "Electrons".
Answer:- 14.0 moles of hydrogen present in 2.00 moles of
.
Solution:- We have been given with 2.00 moles of
and asked to calculate the grams of hydrogen present in it. It's a two step conversion problem. In first step we convert the moles of the compound to moles of hydrogen as one mol of the compound contains 7 moles of hydrogen. In next step the moles are converted to grams on multiplying the moles by atomic mass of H. The calculations are shown as:

= 14.0 g H
So, there are 14.0 g of hydrogen in 2.00 moles of
.
The correct answer is B. Low chemical reactivity