Answer:
The wavelength at which maximum absorbance will be seen is 496.6 nm.
Explanation:
The energy difference between the HOMO and LUMO =E = 2.50 eV
The wavelength at which maximum absorbance will be observed is related to energy of the difference of the HOMO and LUMO.
![E=\frac{hc}{\lambda }](https://tex.z-dn.net/?f=E%3D%5Cfrac%7Bhc%7D%7B%5Clambda%20%7D)
E = energy of photon of related to wavelength
h = Planck's constant = ![6.63\times 10^{-34}Js](https://tex.z-dn.net/?f=6.63%5Ctimes%2010%5E%7B-34%7DJs)
c = speed of light = ![3\times 10^8m/s](https://tex.z-dn.net/?f=3%5Ctimes%2010%5E8m%2Fs)
= wavelength = ?
E = 2.50 eV = ![=2.50\times 1.60218\times 10^{-19} J=4.0054 \times 10^{-19} J](https://tex.z-dn.net/?f=%20%3D2.50%5Ctimes%201.60218%5Ctimes%2010%5E%7B-19%7D%20J%3D4.0054%20%5Ctimes%2010%5E%7B-19%7D%20J)
![\lambda =\frac{6.63\times 10^{-34}Js\times 3\times 10^8 m/s}{4.0054 \times 10^{-19} J}=4.966\times 10^{-7} m](https://tex.z-dn.net/?f=%5Clambda%20%3D%5Cfrac%7B6.63%5Ctimes%2010%5E%7B-34%7DJs%5Ctimes%203%5Ctimes%2010%5E8%20m%2Fs%7D%7B4.0054%20%5Ctimes%2010%5E%7B-19%7D%20J%7D%3D4.966%5Ctimes%2010%5E%7B-7%7D%20m)
![\lambda =496.6 nm (1 m = 10^9 nm)](https://tex.z-dn.net/?f=%5Clambda%20%3D496.6%20nm%20%281%20m%20%3D%2010%5E9%20nm%29)
The wavelength at which maximum absorbance will be seen is 496.6 nm.
Taking into account the definition of density, the density of the sample is 0.5
.
It is necessary yo know that density is defined as the property that matter, whether solid, liquid or gas, has to compress into a given space.
In other words, density allows you to measure the amount of mass in a certain volume of a substance.
Then, the expression for the calculation of density is the quotient between the mass of a body and the volume it occupies:
![density=\frac{mass}{volume}](https://tex.z-dn.net/?f=density%3D%5Cfrac%7Bmass%7D%7Bvolume%7D)
In this case, you know:
Then, replacing in the definition of density:
![density=\frac{6 g}{12 mL}](https://tex.z-dn.net/?f=density%3D%5Cfrac%7B6%20g%7D%7B12%20mL%7D)
Solving:
<u><em>density= 0.5 </em></u>
<u><em /></u>
Finally, the density of the sample is 0.5
.
Learn more about density:
Answer:
![\boxed {\boxed {\sf 0.5 \ M \ NaOH}}](https://tex.z-dn.net/?f=%5Cboxed%20%7B%5Cboxed%20%7B%5Csf%200.5%20%5C%20M%20%5C%20NaOH%7D%7D)
Explanation:
Molarity is a measure of concentration in moles per liter.
![molarity= \frac{moles}{liters}](https://tex.z-dn.net/?f=molarity%3D%20%5Cfrac%7Bmoles%7D%7Bliters%7D)
There are 0.250 moles of sodium hydroxide (NaOH) and 500 milliliters of water. We need to convert milliliters to liters. Remember that 1 liter contains 1000 milliliters.
![\frac{1 \ L}{1000 \ mL}](https://tex.z-dn.net/?f=%5Cfrac%7B1%20%5C%20L%7D%7B1000%20%5C%20mL%7D)
![500 \ mL*\frac{1 \ L}{1000 \ mL}](https://tex.z-dn.net/?f=500%20%5C%20mL%2A%5Cfrac%7B1%20%5C%20L%7D%7B1000%20%5C%20mL%7D)
![500*\frac{1 \ L}{1000 }](https://tex.z-dn.net/?f=500%2A%5Cfrac%7B1%20%5C%20L%7D%7B1000%20%7D)
![\frac{500}{1000} \ L=0.5 \ L](https://tex.z-dn.net/?f=%5Cfrac%7B500%7D%7B1000%7D%20%5C%20L%3D0.5%20%5C%20L)
Now we have the values to solve for molarity:
- moles= 0.250 mol NaOH
- liters= 0.5 L
Substitute the values into the formula.
![molarity= \frac{0.250 \ mol \ NaOH}{0.5 \ L}](https://tex.z-dn.net/?f=molarity%3D%20%5Cfrac%7B0.250%20%5C%20mol%20%5C%20NaOH%7D%7B0.5%20%5C%20L%7D)
Divide.
![molarity= 0.5 \ mol \ NaOH/ L](https://tex.z-dn.net/?f=molarity%3D%200.5%20%5C%20mol%20%5C%20NaOH%2F%20L)
- 1 mole per liter (mol/liter) is equal to 1 Molar or M.
- Our answer of 0.5 moles of sodium hydroxide per liter is equal to 0.5 M NaOH
![molarity= 0.5 \ M \ NaOH](https://tex.z-dn.net/?f=molarity%3D%200.5%20%5C%20M%20%5C%20NaOH)
The molarity of the solution is <u>0.5 M NaOH</u>
Answer:
C. It is hard to recreate the extremely high temperatures and pressures found inside stars.
Explanation:
Nuclear fusion occurs when atomic nuclei are forcefully combined to create a new atomic nuclei or subatomic particles. In nature, this process takes place in our Sun and other stars. Within stars, extremely high temperatures and pressures are achieved and cause nuclear fusion to occur. Humans have not yet been successful in recreating the environment necessary to mimic this process.
Answer:
B) translucent
Explanation:
Light only partially passes through them.