An example.
water is H2O
2 hydrogen, 1 oxygen
so the number to the right means how much of what is on the left.
so it looks like 2, because C2, but look at the 3 at the beginning. that means
3 (c2h4)
so 6 carbons, 12 hydrogen
the ratio of c2 to h4 doesn't change it's always 1:2.
but the 3 at the front is a different number relating to how much you have
Answer:
D
Explanation:
A The calcium chloride dissolves in solution
B The mass of the solution totals 20 g
C The temperature of the solution is 35 degrees
D The solution became lighter in color
The correct answer would be that <u>the solution became lighter in color.</u>
An increase in temperature can also be considered a sign of a chemical reaction but in this case, the dissolution of calcium chloride in water is in itself exothermic.
A change in the mass of the final solution could also be considered a sign of a chemical reaction but in this case, the total mass equals the addition of the individual masses of the reactant.
The dissolution of calcium chloride in water is not enough as evidence of a chemical reaction. Dissolution can be a physical change of which, the evaporation of the water would retrieve the solute.
<em>A change in color, however, is one of the evidence to establish that a chemical reaction has occurred.</em>
The correct option is D.
The kidneys in humans are a part of the system for excretion
Extraction is the process of eliminating waste matter.
