The type of atoms present in the chemical compound and the proportion or how many specific atoms are respect to other atoms in the chemical compound.
Answer:

Explanation:
Regardless of the type of gas, 1 mole at standard temperature and pressure (STP) occupies a volume of 22.4 liters. In this case the gas is helium (He).
We can set up a ratio.

Multiply by the given number of moles.

The moles of helium will cancel.


Multiply.

5.25 moles of helium gas at STP is 117.6 liters of helium.
<span>The energy (E) per photon is expressed by Planck's equation: E = hf, where f is
the frequency and h is Planck's constant, experimentally determined to be
6.625 * 10**-34 joule-seconds. So to find E, we multiply h by the frequency
and obtain E = hf = (6.625 * 10**-34)(7.0 * 10**14) = 46.375 * 10**-20 joule
or in standard notation, E = 4.6375 * 10**-19 joule per photon.
Hope this answers your question.Sorry if I calculated wrong.</span>
Answer:
1-Pentene
Explanation:
If we look at all the options listed, we will notice that the rate of reaction of bromine with each one differs significantly.
For 1-pentene, addition of bromine across the double bond is a relatively fast process. It is usually used as a test for unsaturation. Bromine water is easily decolorized by alkenes.
Cyclohexane, heptane are alkanes. They can only react with chlorine in the presence of sunlight. This is a substitution reaction. It does not occur easily. A certain quantum of light is required for the reaction to occur.
For benzene, bromine can only react with it by electrophilic substitution in which the benzene ring is retained. A Lewis acid is often required for the reaction to occur and it doesn't occur easily.