The human eye contains a molecule called 11-cis-retinal that changes conformation when struck with light of sufficient energy. The change in conformation triggers a series of events that results in an electrical signal being sent to the brain. The minimum energy required to change the conformation of 11-cis-retinal within the eye is about 164 {\rm kJ}/{\rm mol}.
Answer:
The answer to your question is given below
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
Zn + 2HCl —> ZnCl2 + H2
Thus, we can write out the atoms present in both the reactant and the product by doing a simple head count. The atoms present are listed below:
Element >>> Reactant >>> Product
Zn >>>>>>>> 1 >>>>>>>>>> 1
H >>>>>>>>> 2 >>>>>>>>> 2
Cl >>>>>>>>> 2 >>>>>>>>> 2
For a candle to burn, it requires a spark, which provides the activation energy for the oxidation reaction of the hydrocarbon making the candle.
It also requires oxygen to facilitate the oxidation of the hydrocarbon.
Therefore the two main requirements of combustion of a candle are oxygen and a spark (or an initial flame)
Do we get multiple choice
You would use this number, 6.02×1023 (Avogadro's number) to convert from particles, atoms, or molecules to moles. Whenever you go to the mole, divide by Avogadro's number. When you go to the unit from moles, multiply by Avogadro's number.