The answer is Letter C. It includes all bodies of water or what is left of it.
If the heating is done on one small area on the top, there will be convection. If the heating is restricted to a small fraction of the heating area, then within that area the heating will go deeper than anywhere else on the surface. Then unheated area will have a shallower region of high temperature. Then some convection will occur in the deeper layers, causing some motion on top.
This happens quite a bit during welding. Convection is very significant in welding, even when the heating is from the top.
Answer: 48800g
Explanation:
Using the mathematical relation : Moles = Mass / Molar Mass
Moles = 488
Molar mass of CaCO3 = 40 + 12 + (16 x 3) = 100g/mol
Therefore
488 = mass / 100 = 48800g
The number of grams of Ca) needed to produce 42.0 g of Hg is calciulated as below
4 HgS + 4CaO = 4 Hg + 3 Cas +CaSO4
calculate the moles of Hg produced
moles=mass/molar mass
moles of Hg = 42 g/200.59 g/mole = 0.2094 moles
by use of mole ratio of Cao:Hg which is 4:4 the moles of CaO = 0.2094 x4/4 =0.2094 moles
mass of CaO=moles x molar mass of CaO
mass of caO=0.2094 x56 = 11.73 grams