<u>Answer:</u> The correct answer is Option D.
<u>Explanation:</u>
Enthalpy change is defined as the difference in enthalpies of all the product and the reactants each multiplied with their respective number of moles. It is represented as 
The equation used to calculate enthalpy change is of a reaction is:
![\Delta H^o_{rxn}=\sum [n\times \Delta H^o_f_{(product)}]-\sum [n\times \Delta H^o_f_{(reactant)}]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28product%29%7D%5D-%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28reactant%29%7D%5D)
Hence, the correct answer is Option D.
30. mixture of compounds
31. compound
32. element
33. compound
34. compound
34. mixture of elements and compounds
Mercury (Metal) is in liquid form at room temperature
Bromine (Non-Metal) is in liquid form at room temperature
Most of the elements are solid, 11 gases and 6 liquids
Answer:
The 3rd option is correct
Explanation:
The element in group 13 and period 3 is aluminium which has the electron configuration
or [Ne] 3s^2 3p^1
