Answer:
Can I get my 50 points now?
Explanation:
The helium is formed during the natural radioactive decay of elements such as uranium and thorium. These heavy elements were formed before the earth but they are not stable and very slowly, they decay. One mode of decay for uranium is to emit an alpha-particle.
Gold potential is the correct answer
Answer:
Stone A
Explanation:
Measuring density is an easiest way to determine if two similar looking substances are same or not. Here also we need to perform the density test for each stone that is suspected to be fake diamond. We will calculate the density of each stone and compare it with the density of original diamond.
Density is calculated using the formula
It has been given in the question that both the substances have same volume of 0.15 
.
Density of stone A = 
= 3.47 
or after rounding off we get 3.5
Density of stone B = 
= 2.8
It is clear from the above calculation that the stone A has same density as the diamond but stone B lacks behind in density.
So, stone A could be the real diamond.
The balanced chemical reaction would be
<span>fecl2 + 2naoh = fe(oh)2(s) + 2nacl
Initial amounts of the reactants are given, so, we need to determine which of the reactants is the limiting reactant and use this amount to determine what is asked. However, what is being asked is how many of the FeCl2 is used in the reaction, showing that it is NaOH that is the limiting reactants. Thus, we just use the initial amount of NaOH and relate the substances by the chemical reaction as follows:
6 mol NaOH ( 1 mol FeCl2 / 2 mol NaOH ) = 3 mol FeCl2
Therefore, 3 moles of FeCl2 is used up and 3 moles of FeCl2 is also left after the reaction.</span>
