The third answer is the one you want. You have to have an adjustable density. All other things being equal, if the tanks you use for holding just water when filled with water will let the sub sink, because the sub is made of a dense metal like iron or steel.
If on the other hand you fill these tanks with air, the net density will be below one and the sub will rise.
Moles of water atoms = mass/molecular weight = 105/18 = 5.83 mol. Number of moles of hydrogen in water = 2 x moles of water = 11.66. Number of H atoms in water = moles of hydrogen x 6.02 x 10^23 = 7.019 x 10^24 ~ 7.02 x 10^24 atoms. Hope this helps.
Calcium fluoride.
Ca is metal, F is non-metal, so they form ionic bond.
Ca as metal can form only positive ion. Ca in the second group, so the charge of Ca ion is 2+. Ca²⁺
F is in the 17th group, so it has 7 electrons on the last level. It is non-metal, non-metal, so it has negative charge -(8-7)=-1. "8" because on the last level cannot be more than 8 electrons. F-ion is F¹⁻.
Ca²⁺ F¹⁻
Number of positive charges should be equal to number of negative charges,
Formula of calcium fluoride
CaF2.
2 atoms Fluorine bond with Calcium.
Answer:
1.53 atm
Explanation:
From the question given above, the following data were obtained:
Volume = constant
Initial pressure (P₁) = stp = 1 atm
Initial temperature (T₁) = 273 K
Final temperature (T₂) = 144 °C = 144 °C + 273 = 417 K
Final pressure (P₂) =?
Since the volume is constant, the final pressure can be obtained as follow:
P₁ / T₁ = P₂ / T₂
1 / 273 = P₂ / 417
Cross multiply
273 × P₂ = 417
Divide both side by 273
P₂ = 417 / 273
P₂ = 1.53 atm
Therefore, the final pressure (i.e the pressure inside the hot water bottle) is 1.53 atm.
