Explanation:
how are you confused there just tell me the problem
Answer:
It takes 86 days take to cover half of the lake
Explanation:
In the day #1, the amount of the algae is X,
In the day #2 is 2X
In the day #3 is 2*2*X = X*2²
...
In the day #n the amount of the algae is X*2^(n-1)
Assuming X = 1m³. In the day 87, the area infected was:
1m³*2^(87-1)
7.74x10²⁵m³ is the total area of the lake
the half of this amount is 3.87x10²⁵m³
The time transcurred is:
3.87x10²⁵m³ = 1m³*2^(n-1)
Multiplying for 5 in each side:
ln (3.87x10²⁵) = ln (2^(n-1))
58.9175 = n-1 * 0.6931
85 = n-1
86 = n
<h3>It takes 86 days take to cover half of the lake</h3>
Answer:
C. To determine how efficient reactions are.
D. To determine how much reactant they need.
Explanation:
When you are doing a reaction, you are hoping for a percent yield to close of 100%. You make the reaction and determine how many product you obtain. If you know the percent yield of a reaction you can calculate the amount of reactant you need to obtain a determined amount of product.
Having this in mind:
A. To balance the reaction equation. false. To calculate percent yield you need to balance the reaction before. You don't use percent yield to balance the reaction
B. To determine how much product they will need. false. You determine how much product you obtain after the reaction. How much product you need is independent of percent yield
C. To determine how efficient reactions are. true. A way to determine efficience of a reaction is with percent yield. An efficient reaction has a high percent yield.
D. To determine how much reactant they need. true. If you know percent yield of a reaction you can know how many reactant you must add to obtain the amount of product you want.
Soap has both a polar end and a nonpolar end. Thus, it maybe soluble to most of the substances. It exhibits both properties of non-polar and polar molecules. The hydrocarbon chain is the non-polar side while the salt end is the polar end.
C. Convection currents in the air
Explanation:
Near the shore, winds tends to blow out towards the water at night and this is driven by convection currents in the air.
Convection occurs in fluids. Since we are dealing with wind, therefore, it is convection in air.
- At night, the air on land is cold and under high pressure.
- The shore area is able lose and gain heat very fast.
- At night, since the shore is cold, the air around is cold too.
- The ocean has high heat capacity and does not lose or gain heat easily.
- At night, it still retains come of its heat.
- This causes nearby winds to warm up, becomes less dense and rises.
- The wind here is moves towards the cold land
- The breeze on land moves outwards towards the ocean.
- This will then set up convection currents.
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