<span>Endothermic Reaction. This reaction or process absorbs energy from its surroundings, mostly, but will not always be, in form of heat. A reaction that requires the input of energy that breaks a bond will always be endothermic. Best examples of endothermic reaction are: 1) melting cubes; 2) evaporating of liquid; 3) melting solid salts, etc.</span>
3-B
4-C
5-A
6-A
7-C
8-B
9-A
10-B
C. KOH + HBr → KBr + H₂O
Explanation:
The two equations above illustrates the conservation of matter. The law of conservation of matters states that
"in a chemical reaction, matter is neither created nor destroyed but transformed from one form to another".
By this law, we understand that the amount of a particular matter we are starting with should be the one we end with.
KOH + HBr → KBr + H₂O
Conserving Product Reactants
K 1 1
O 1 1
H 2 2
We can see that the amount on both sides are the same.
Learn more:
Conservation of matter brainly.com/question/2190120
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Answer:
the reaction was that it turned green. because it used to be brown but because the rain and carbon dioxide affected it.
This question is dealing with the half-life of carbon-14 which can be used to determine the age of a substance according to the following equation:
t = [ln(N/No)/(-ln2)] · t1/2
N = # of carbon-14 atoms presently = 250 atoms
No = # of carbon-14 atoms initially = 1000 atoms
t1/2 = half-life = 5730 years for carbon-14
We can now input all of the information into the formula to find the age of the fossil:
t = [ln (250/1000)/-ln2] x 5730 years
t = 11460 years
The fossil should be found to be roughly 11,460 years old.
