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almond37 [142]
3 years ago
7

When the hydrogen atom makes the transition from the n=2 to the n=1 energy level, it emits a photon. This photon can be absorbed

by to a singly ionized helium atom (He+) in its second energy level (ninitial=2), causing it to move to a higher energy level. To what final energy level number nfinal can the photon promote the helium ion?
Note that He+ has two protons in its nucleus and a single electron.
Physics
1 answer:
bazaltina [42]3 years ago
8 0

Answer:

n_{fn}= 4

Explanation:

To solve this exercise we will use Bohr's atomic model

               E_{n} = - 13.606 / n²     [eV]

The transition from level n = 2 to level n = 1 is valid

               E_{21} = - 13.606 [¼ -1/1]

               E_{21} = 10.2045 eV

Bohr's model for atoms with only one electron is

               E_{n} = -13.606 Z² / n²

Where Z is the atomic number of the atom.

In this case the helium atom has an atomic number of Z = 2 from the level n₀ = 2 let's look up to what level it reaches

         ΔE = -13.606 [4 /  n_{fn}² - 4/4]

         4 / n_{fn}² = -ΔE / 13.606 + 1

         4 / n_{fn}² = -10.2045 / 13.606 +1 = -0.75 +1

         4 / n_{fn}² = 0.25

        n_{fn} = √ 4 / 0.25

        n_{fn}= 4

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Answer:

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Explanation:

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Can someone please help me with this physics question? I'm desperate!
Lelu [443]

Answer:

a) 2·√10 seconds

b) Linda should be approximately 30.6 meters

c) Jenny's speed at the 100-m mark is approximately 6.325 m/s

Explanation:

The speed with which Linda is running = 8.6 m/s

The point Jenny starts = The 80-m mark

The acceleration of Jenny = 1.0 m/s²

a) The time it takes Jenny to run from the 80-m mark to the 100-m mark, <em>t</em>, is given as follows

Δs = u·t + (1/2)·a·t²

Δs = Distance = 100-m - 80-m = 20-m

u = The initial velocity of Jenny = 0

a = Jenny's acceleration = 1.0 m/s²

∴ 20 = 0×t + (1/2) × 1 × t² = t²/2

20 = t²/2

t = √(20 × 2) = 2·√10

The time it takes Jenny to run from the 80-m mark to the 100-m mark = 2·√10 seconds

b) The distance Linda runs in t = 2·√10 seconds, d = v × t

Given that Linda's velocity, v = 8.6 m/s, we have;

d = 8.0 × 2·√10 = 16·√10

The distance Linda runs in t = 2·√10 seconds = 16·√10 meters ≈ 50.6 meters

Therefore, Linda should be approximately (50.6 - 20) meters = 30.6 meters behind Jenny when Jenny starts running

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v = u + a·t

t = 2·√10 seconds, a = 1.0 m/s², u = 0

∴ v = 0×t + 1.0×2·√10 = 2·√10 ≈ 6.325

Jenny's speed at the 100-m mark ≈ 6.325 m/s

3 0
2 years ago
A 60-watt light bulb has a voltage of 120 volts applied across it and a current of 0.5 amperes flows through the bulb. What is t
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V=120volts

From ohms law

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R= 240ohms

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