(1) IS THE BALANCED EQUATION AND REACTANT-> MG AND N2 AND PRODUCT ->MGN2.
(2) IS NOT BALANCED AND REACTANT->CF4 AND BR AND PRODUCT IS CBR4 AND F2
Answer:
About 60.
Explanation:
Mendeleev knew of 63 elements. He wrote their properties on cards and arranged them in order of atomic mass.
That's how he discovered that the properties of elements are periodic functions of their atomic masses.
Answer : The heat of the reaction is -221.6 kJ
Explanation :
Heat released by the reaction = Heat absorbed by the calorimeter
where,
= heat released by the reaction = ?
= heat absorbed by the calorimeter
= specific heat of calorimeter = 
= change in temperature = 
Now put all the given values in the above formula, we get:
As,
So, 
Thus, the heat of the reaction is -221.6 kJ
Elements are represented by their symbols with the first letter capitalized and the rest in lowercase. Copper is represented by Cu and Bromine is represented by Br. When combined to for a compound, the format of the symbols remain. Hence, the correct format would be CuBr.
Thus, the answer is C: CuBr<span>.</span><span />
