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3 years ago

Calculate the frequency required to eject electrons from gold with a work function of 8.76 x 10-19 J

1 answer:

5 0

$hf=W+\frac{mv^{2}}{2}\\\\
f=\frac{W+\frac{mv^{2}}{2}}{h}\\\\\

W=8,76*10^{-19}J\\
m=9,11*10^{-31}kg\\
v=3*10^{8}\frac{m}{s}\\
h=6,63*10^{-34}Js\\\\\\
f=\frac{8,76*10^{-19}J+\frac{9,11*10^{-31}kg*(3*10^{8}\frac{m}{s})^{2}}{2}}{6,63*10^{-34}Js}=7,5*10^{19}Hz$

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2 years ago

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Answer:

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In nuclear magnetic resonance you are looking for peaks specific for atoms in your desired compound (H or C atoms). When external magnetic field is applied, atom goes in higher energy state. When atoms goes "relaxing", it releasing energy that mach energy gap from relaxed end excited state. That energy is detected on nuclear magnetic resonance spectra and it depends on neighbor atom so you can determine the position of atoms and identify structure of desired compound.

For better results it is the best to combine these two methods.

Explanation:

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3 years ago

How many moles of neon occupy a volume of 14.3 l at stp? how many moles of neon occupy a volume of 14.3 l at stp? 1.57 moles 0.6

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The number of neon moles that occupy a volume of 14.3 l at STP is calculated as follows

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3 years ago

I need to know the following above

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3 years ago

The concentration of protein in a urine sample is calculated to be 2.77 μg/mL. What is the concentration of this solution in uni

maxonik [38]

Answer:

The concentration of this solution in units of pounds per gallon is $2.776*10^{-5} \frac{lb}{gal}$

Explanation:

Units of measurement are established models for measuring different quantities. The conversion of units is the transformation of a quantity, expressed in a certain unit of measure, into an equivalent one, which may or may not be of the same system of units.

In this case, the conversion of units is carried out knowing that 1 μg are equal to 2.205*10⁻⁹ Lb and 1 mL equals 0.00022 Gallons. So

$2.77 \frac{ug}{mL} = \frac{2.77 ug}{mL}$

If 1 μg equals 2.205*10⁻⁹ lb, 2.77 μg how many lb equals?

$lb=\frac{2.77ug*2.205*10^{-9}lb }{1ug}$

lb=6.10785*10⁻⁹

So, 2.77 μg= 6.10785*10⁻⁹ lb

Then:

$2.77 \frac{ug}{mL} = \frac{2.77 ug}{mL}=\frac{6.10785*10^{-9}lb }{mL} =\frac{6.10785*10^{-9}lb }{0.00022 gal} =\frac{6.10785*10^{-9}lb }{0.00022 gal}$

You get:

$2.77 \frac{ug}{mL} = 2.776*10^{-5} \frac{lb}{gal}$

The concentration of this solution in units of pounds per gallon is $2.776*10^{-5} \frac{lb}{gal}$

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3 years ago