The electron is travelling with a velocity of 1.123 × 10⁷m/s if it has a wavelength of 8.20 km.
<h3>How to calculate velocity of an electron?</h3>
The velocity at which an electron travels can be calculated using the following formula:
λ = h/mv
Where;
- H = Planck's constant
- m = mass of electron
- v = velocity of electron
- λ = wavelength
- Planck's constant (h) = 6.626 × 10−³⁴ J⋅s.
- mass of electron (m) = 9.109 × 10−³¹ kg
- wavelength = 8200m
8200 = 6.626×10−³⁴ / 9.109 × 10−³¹V
8200 = 7.3 × 10-⁴V
V = 8200 ÷ 7.3 × 10-⁴
V = 1.123 × 10⁷m/s
Therefore, the electron is travelling with a velocity of 1.123 × 10⁷m/s if it has a wavelength of 8.20 km.
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The 2nd one I believe
Answer- 2nd
Answer:
Explanation:
<u><em>What is the potential energy of a 2-kg book sitting on a shelf 2 meters above the ground?</em></u>
<em></em>
PE = MGH, that is, potential energy = mass x gravity x height.
2*2*9.8=
39.2 joules
Taking into account the definition of molarity, the concentration of the solution is 0.855 
.
<h3>Definition of molarity</h3>
Molar concentration or molarity is a measure of the concentration of a solute in a solution and indicates the number of moles of solute that are dissolved in a given volume.
The molarity of a solution is calculated by dividing the moles of solute by the volume of the solution:
Molarity is expressed in units .
<h3>Molarity of NaCl</h3>
In this case, you have:
- number of moles of NaCl=
1.71 moles (being 58.45 g/mole the molar mass of NaCl) - volume 2 L
Replacing in the definition of molarity:
Solving:
Molarity= 0.855
Finally, the concentration of the solution is 0.855 .
Learn more about molarity:
<u>brainly.com/question/9324116</u>
<u>brainly.com/question/10608366</u>
<u>brainly.com/question/7429224</u>
