This is due to the difference in density. The rock is
denser than the leaf. And also, the rock is denser than the liquid in the pond.
If the material is denser than the other material, it will sink. The same holds
true for the rock, it sinks. But when the material is less dense than the other
material, it floats. And it holds true for the leaf, it floats.
It’s can go down to 50 degrees soo that can do
Answer:
1) When 6.97 grams of sodium(s) react with excess water(l), 56.0 kJ of energy are evolved.
2) When 10.4 grams of carbon monoxide(g) react with excess water(l), 1.04 kJ of energy are absorbed.
Explanation:
1) The following thermochemical equation is for the reaction of sodium(s) with water(l) to form sodium hydroxide(aq) and hydrogen(g).
2 Na(s) + 2H₂O(l) ⇒ 2NaOH(aq) + H₂(g) ΔH = -369 kJ
The enthalpy of the reaction is negative, which means that 369 kJ of energy are evolved per 2 moles of sodium. The energy evolved for 6.97 g of Na (molar mass 22.98 g/mol) is:

2) The following thermochemical equation is for the reaction of carbon monoxide(g) with water(l) to form carbon dioxide(g) and hydrogen(g).
CO(g) + H₂O(l) ⇒ CO₂(g) + H₂(g) ΔH = 2.80 kJ
The enthalpy of the reaction is positive, which means that 2.80 kJ of energy are absorbed per mole of carbon monoxide. The energy evolved for 10.4 g of CO (molar mass 28.01 g/mol) is:

Answer:
molar mass of carbon tetrafluoride (CF4) is
(12.01 × 1 ) + ( 4 × 19.00)
= 12.01 + 76
= 88.01u
= 88u
Hope this helps