Answer:
The correct answer is - sulfur.
Explanation:
In the periodic table, there are 18 groups and 7 rows or periods arranged according to their atomic number or electronic configuration. In the question, it is mentioned that the desired element atomic mass is less than the atomic mass of the selenium which is 78.96, and more than oxygen which is 15.99 with 6 electron valence and present in the third row.
As it has 6 valency of electron it must be in the 16 group of the table that comprises the 6 valency and as it is located in the 3rd row it must be sulfur that also has an atomic mass between selenium and oxygen.
The differences are the freezing and boiling points being exactly 180 degrees
Answer:
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Reaction:
Magnesium is a stronger reducing agent than copper and is thus able to reduce copper(II) oxide.
Products of the reaction: Magnesium oxide and metallic copper.
Answer : To determine enthalpy of solution for a solid with δH values.
One can use the equation as H (reaction) = H (products) - H (reactants)
If δH values are known one can simply substitute them in the above equation and get the enthalpy of the required solution.
