Answer:
5 atoms are in each molecule of calcium carbonate
Answer:
Element Helium have<u> 2 energy levels. </u>
Explanation:
<u>HELIUM -</u> With the symbol He and the atomic number 2, helium is a chemical element. It is a colorless , odorless, tasteless, non-toxic, inert, monatomic gas that is the first in the periodic table in the noble gas group. Of all the elements, its boiling point is the lowest.
At about 24 % of the total elemental mass, which is more than 12 times the mass of all the heavier elements combined, it is present. In both the Sun and Jupiter, its abundance is identical to this. This is due to helium-4's very high nuclear binding energy (per nucleon) with respect to the next three elements following helium.
<u>Hence , the answer is 2 energy levels in Helium atom.</u>
Answer:
It is not possible
Explanation:
Nitrogen is a light gas that find application in my areas including being used to keep things cold.It has a freezing point of -210°c so the scientist Nitrogen in the question at 100°c have already freezed and no longer a liquid.
a b c d no a no b yes c no d ok
The given chemical equation is:
On balancing the equation we get,
Calculating enthalpy of formation of this reaction from the standard heats of formation of the products and reactants:
Δ![H_{reaction}^{0}=[H_{f}^{0}(Al_{2}O_{3}(s)) + (3*H_{f}^{0}(H_{2}SO_{4}(aq))] - [H_{f}^{0}(Al_{2}SO_{4}(aq)) + (3*H_{f}^{0}(H_{2}O(l))]](https://tex.z-dn.net/?f=H_%7Breaction%7D%5E%7B0%7D%3C%2Fp%3E%3Cp%3E%3D%5BH_%7Bf%7D%5E%7B0%7D%28Al_%7B2%7DO_%7B3%7D%28s%29%29%20%2B%20%283%2AH_%7Bf%7D%5E%7B0%7D%28H_%7B2%7DSO_%7B4%7D%28aq%29%29%5D%20-%20%20%20%5BH_%7Bf%7D%5E%7B0%7D%28Al_%7B2%7DSO_%7B4%7D%28aq%29%29%20%2B%20%283%2AH_%7Bf%7D%5E%7B0%7D%28H_%7B2%7DO%28l%29%29%5D)
=[(-1669.8kJ/mol)+ {3* (-909.27 kJ/mol)}]-[(-3442kJ/mol)+{3*(-285.8 kJ/mol)}]
=[(-4397.61kJ/mol)]-[(-4299.4kJ/mol)]
=-98.21kJ/mol
Total enthalpy change when 15 mol of 
reacts will be=
