Answer:
Option C. The same number of energy levels.
Explanation:
From the diagram given above, element (i) belong to group 2 while element (ii) belong to group 6.
Also, both element i and ii belong to the same period (i.e period 4). This simply means that both element i and ii have the same number of energy levels.
NOTE: Elements in the same period have the same number of shells of electrons which simply means they have the same energy levels.
Hi.
You can calculate mass percent by dividing the mass by the total mass of the compound & multiplying by 100.
28.8 ÷ (171.2 + 28.8) = 0.144
0.144 · 100 = 14.4
I believe the mass percent of the hydrogen in the compound is 14.4%
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A calorimeter experiment is a set-up that provides insulation so that no heat escapes to the surroundings and all energy can be accounted for. It can be done at either constant volume or constant pressure. So, the answer to this is knowing the mass of water, the specific heat which is an empirical data, and the change in temperature which can be measured using a thermometer. This experiment could measure the mass of an unknown substance added or the specific heat of the substance or the calorimeter. <em>The answer is D.</em>
It is group 16. That is, Chalcogens. They call it the oxygen family.
Reactant C is the limiting reactant in this scenario.
Explanation:
The reactant in the balanced chemical reaction which gives the smaller amount or moles of product is the limiting reagent.
Balanced chemical reaction is:
A + 2B + 3C → 2D + E
number of moles
A = 0.50 mole
B = 0.60 moles
C = 0.90 moles
Taking A as the reactant
1 mole of A reacted to form 2 moles of D
0.50 moles of A will produce 
= 
thus 0.50 moles of A will produce 1 mole of D
Taking B as the reactant
2 moles of B reacted to form 2 moles of D
0.60 moles of B reacted to form x moles of D
= 
x = 2 moles of D is produced.
Taking C as the reactant:
3 moles of C reacted to form 2 moles of D
O.9 moles of C reacted to form x moles of D
= 
= 0.60 moles of D is formed.
Thus C is the limiting reagent in the given reaction as it produces smallest mass of product.
