What are the 4 kingdoms listed in the Eukarya Domain? List all 4 Kingdoms

calculate the speed of an electron if its de broglie wavelength is twice its displacement in one second

valkas [14]

Answer:

The speed of an electron is 0.01908 m/s.

Explanation:

De-Broglie wavelength is given by:

$\lambda=\frac{h}{mv}$

where, $\lambda$ = wavelength of a particle

h = Planck's constant = $6.626\times 10^{-34}Js$

m = mass of particle

v = velocity of the particle

Velocity of an electron = v

Mass of an electron = $9.1\times 10^{-31}kg$

Wavelength of electron is twice the displacement in seconds which is velocity of an electron.

Then.wavelength of an electron = $\lambda =2v$

$\lambda =2v=\frac{6.626\times 10^{-34}Js}{9.1\times 10^{-31}kg\times v}$

v = 0.01908 m/s

The speed of an electron is 0.01908 m/s.

5 0

3 years ago

What is Centripetal force?

makvit [3.9K]

A. A force that acts on a body moving in a circular path

6 0

3 years ago

Is it possible to see the tiny particles that make up a grain of sand

77julia77 [94]

Technically speaking, yes you can. Using a microscope though.

6 0

3 years ago

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Baking soda and vinegar can be used to model a volcanic eruption in a science demonstration because they bubble violently when m

julia-pushkina [17]

<span>Vinegar and baking soda react to form a new gaseous substance.

</span><span>The reaction between Vinegar and baking soda has been one of the most common examples of Chemical Reaction.</span>

4 0

3 years ago

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Suppose a group of volunteers is planning to build a park near a local lake. The lake is known to contain low levels of arsenic

Kisachek [45]

Answer:

A) 10.75 is the concentration of arsenic in the sample in parts per billion .

B) 7,633.66 kg the total mass of arsenic in the lake that the company have to remove.

C) It will take 1.37 years to remove all of the arsenic from the lake.

Explanation:

A) Mass of arsenic in lake water sample = 164.5 ng

The ppb is the amount of solute (in micrograms) present in kilogram of a solvent. It is also known as parts-per million.

To calculate the ppm of oxygen in sea water, we use the equation:

$\text{ppb}=\frac{\text{Mass of solute}}{\text{Mass of solution}}\times 10^9$

Both the masses are in grams.

We are given:

Mass of arsenic = 164.5 ng = $164.5\times 10^{-9} g$

$1 ng=10^{-9} g$

Volume of the sample = V = $15.3 cm^3$

Density of the lake water sample ,d= $1.00 g/cm^3$

Mass of sample = M = $d\times V=1.0 g/cm^3\times 15.3 cm^3=15.3 g$

$ppb=\frac{164.5\times 10^{-9} g}{15.3 g}\times 10^9=10.75$

10.75 is the concentration of arsenic in the sample in parts per billion.

B)

Mass of arsenic in $1 cm^3$ of lake water = $\frac{164.5\times 10^{-9} g}{15.3}=1.075\times 10^{-8} g$

Mass of arsenic in $0.710 km^3$ lake water be m.

$1 km^3=10^{15} cm^3$

Mass of arsenic in $0.710\times 10^{15} cm^3$ lake water :

$m=0.710\times 10^{15}\times 1.075\times 10^{-8} g=7,633,660.130 g$

1 g = 0.001 kg

7,633,660.130 g = 7,633,660.130 × 0.001 kg=7,633.660130 kg ≈ 7,633.66 kg

7,633.66 kg the total mass of arsenic in the lake that the company have to remove.

C)

Company claims that it takes 2.74 days to remove 41.90 kilogram of arsenic from lake water.

Days required to remove 1 kilogram of arsenic from the lake water :

$\frac{2.74}{41.90} days$

Then days required to remove 7,633.66 kg of arsenic from the lake water :

$=7,633.66\times \frac{2.74}{41.90} days=499.19 days$

1 year = 365 days

499.19 days = $\frac{499.19}{365} years = 1.367 years\approx 1.37 years$

It will take 1.37 years to remove all of the arsenic from the lake.

3 0

3 years ago