Answer:
66.7s
Explanation:
Let's bring out the parameters we were given...
Half life = ?
Initial Concentration = 0.0576 M
Final Concentration = 0.0249 M
Time for the concentration change to occur = 97.8s - 17.1s = 80.7s
Formular for half life (t1/2) is given as;
t1/2 = ln2 / k ≈ 0.693 / k
where k = rate constant
From the formular of first order reactions;
ln[A] = ln[A]o − kt
where [A] = Final Concentration and [A]o = Initial Concentration
Inserting the values, we have;
ln(0.0249) = ln(0.0576) - k(80.7)
Upon solving for k, we have;
-0.8387 = -k(80.7)
k = 0.01039 s−1
t1/2 = 0.693 / k = 0.693 / 0.01039 = 66.7s
Answer:
a. volcanic changes create new land
Answer:
2+
Explanation:
Nickel has an atomic number of 28 meaning that it contains 28 protons in its nucleus. It would need 28 electrons in order to have no charge, because the positive and negative charges balance each other out. Since this atom of Ni has 26 electrons, it has lost 2 of its electrons, and therefore has a positive charge of 2.
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