Answer:
3.
Explanation:
Hello,
In this case, it is convenient to write the chemical reaction as:
Which balanced turns out:
Thus the number that should be in front of the calcium sulfate is 3 in order to balance the reaction.
Best regards.
Answer:
Half-Life = 18 days
Explanation:
Isotope decay follows the equation:
Ln[A] = -kt + ln[A]₀
<em>Where [A] is amount of isotope after time t,</em>
<em>k is rate constant</em>
<em>[A]₀ is initial amount of isotope.</em>
<em> </em>
If we solve rate constant, we can find half-life by using:
Half-life = ln 2 / Rate constant
Replacing in isotope decay equation:
Ln[1/8] = -k*54 days + ln[1]
-2.07944 = -54k
0.0385days⁻¹ = k
Half-Life = ln 2 / 0.0385days⁻¹
<h3>Half-Life = 18 days</h3>
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The electron gain for iron means that it is reduced (answer C)
Explanation
Redox reaction is made up of two halves.
That is a reduction half and a oxidization half.
In the reduction half electrons are gained which result to decrease in oxidation number.
In the Oxidization half electrons are lost which result to increase in oxidation number.
iron is therefore reduced since it gains electrons
Answer:
Physical change: A,C ,D, F, H, I
Chemical Change: B, E, G, J, K