You would want to make sure that you have controlled the variables properly, and if you determine that you did then you would repeat the experiment to be sure of the results.
Release less energy than it uses
Half life is the time taken by a radioactive isotope to decay by half its original mass. In this case, the halflife of the radioactive isotope is 5000 years.
Initially the mass is 100 %; thus the mass that will be left will be given by;
New mass = Original mass × (1/2)^n where n is the number of half lives;
n = 10000/5000 = 2
New mass = 100% ×(1/2)^2
= 100 % × 1/4
= 25%
Therefore; the mass left after 10000 years is 25% or 1/4 of the original mass.
The purpose is that it shows you all the elements we know and it arranges them in groups that are also the same kind like Chemistry.
Answer:
The oxidation state of the carbon is +4.
Explanation:
Calcium is in group 2 of the periodic table, therefore, its oxidation state is +2.
The oxidation state of the oxygen is -2.
As the compound is neutral, the sum of the oxidation states of all atoms must be 0.
Oxidation State Ca + Oxidation State C + (Oxidation State O)×3 = 0
+2 + x + (-2)×3 = 0
2 + x - 6 = 0
x = 6 -2
x = 4
Hence, the oxidation state of the carbon is +4.
