<u>Answer:</u> The correct answer is Option A.
<u>Explanation:</u>
Standard enthalpy of formation is the change in enthalpy of one mole of a substance present at the standard state that is 1 atm of pressure and 298 K of temperature. The substance is formed from its pure elements under the same conditions.
We are given a chemical compound having chemical formula 
This compound is formed by the combination of calcium, nitrogen and oxygen elements.
The chemical equation for the formation of from the components in their standard states follows:
Hence, the correct answer is Option A.
<h2>
Answer:</h2>
Hey,
<h3><u>
QUESTION)</u></h3>
The mass of 6,022 × 10²³ molecules of a substance is called its molar mass.
- In fact this number represents the Avogadro Constant characteristic of the number of entities contained in a mole.
Molecular hydrogen (H2)
Hydrogen (H2O2)
Nirous Oxide (N2O)
Methane (CH4)
I am so sorry if this is incorrect I did it a long time ago!
A) The atomic mass can vary based on the number of neutrons the atoms of the same element have, so the atomic mass may not be in order. Also, the atomic number is unique to each element.
Hope this helped!
Explanation:
Here's what I came up with :)
