<span>When a chemical reaction occurs and the thermometer in the container records a drop in temperature t</span>he reaction is exothermic because heat was released by the reaction.
<span>B. The reaction is exothermic because heat was released by the reaction. is your answer.
Hoped I helped!</span>
Answer:
Mass = 9.58 g
Explanation:
Given data:
Mass of Zn = 2g
Theoretical yield of ZnI₂ = ?
Solution:
Chemical equation:
Zn + I₂ → ZnI₂
Number of moles of Zn:
Number of moles = mass/molar mass
Number of moles = 2g / 65.38 g/mol
Number of moles = 0.03 mol
Now we will compare the moles of Zn and ZnI₂.
Zn : ZnI₂
1 : 1
0.03 : 0.03
Mass of ZnI₂:
Mass = number of moles × molar mass
Mass = 0.03 mol × 319.22 g/mol
Mass = 9.58 g
Element X is sodium.
If there is one more shell of electrons, then this means it is one period below.
Since there is one less valence electron, it is one group to the left.
