Q: A neutron is confined to a region of space with an uncertainty in position of $$0.30 nm. $$What is the minimum uncertainty in its momentum? ($$h = 6.626 \times 10$$^{-34}$$ J·s)

$$5.53 \times 10$$^{-25}$$ kg\cdot m/s$

Question 1

A laser emits light with a wavelength of 340 nm. What is the frequency of this light? (Speed of light $$c = 3.00 	imes 10^8$ m/s)

Accepted Answer

$$8.82 	imes 10$$^{14}$$ Hz

Question 2

Which of the following statements best describes the difference between constructive and destructive interference?

Accepted Answer

Constructive interference occurs when waves are in phase, resulting in increased amplitude, while destructive interference occurs when waves are out of phase, resulting in cancellation.

Question 3

A photon from a xenon lamp has an energy of $$1.66 	imes 10$$^{-19}$$ J. What is the wavelength of this photon in nm? (Planck's constant h = 6.626$$ 	imes $$10^{-34} J$$·s, $$c = 3.00 	imes 10^8$ m/s)

Accepted Answer

$$1.20 	imes 10$$^{3}$$ \ nm$

Question 4

Which region of the electromagnetic spectrum has the highest energy photons?

Accepted Answer

Gamma rays

Question 5

According to the Bohr model, what happens when an electron in a hydrogen atom transitions from $$n=5 to$$ $$n=2$$?

Accepted Answer

A photon is emitted with energy equal to the difference between the two energy levels.

Question 6

Calculate the energy (in J) of an electron in the $$n=3$$ state of a hydrogen atom. Use $$E_n = -2.18 	imes 10$$^{-18}$$ \left( \frac{1}{n^2$} ight) J.$$

Accepted Answer

$$-2.42 	imes 10$$^{-19}$$ J

Question 7

Which of the following quantum number sets is NOT allowed for an electron in an atom?

Accepted Answer

$$n=4, \ l=4, \ m_l=+2, \ m_s=+1/2$$

Question 8

What is the de Broglie wavelength (in m) of an electron moving at $$5.00 	imes 10^6$ m/s? (mass of electron = 9.11$$ 	imes $$10^{-31} kg$$, $$h = 6.626 	imes 10$$^{-34}$$ J·s)

Accepted Answer

$$1.45 	imes 10$$^{-10}$$ m

Question 9

Which quantum number determines the shape of an atomic orbital?

Accepted Answer

Angular momentum quantum number ($$l)$$

Question 10

A neutron is confined to a region of space with an uncertainty in position of $$0.30 nm. $$What is the minimum uncertainty in its momentum? ($$h = 6.626 	imes 10$$^{-34}$$ J·s)

Accepted Answer

$$5.53 	imes 10$$^{-25}$$ kg\cdot m/s$

Question 11

Which of the following best describes the Heisenberg Uncertainty Principle?

Accepted Answer

It is impossible to know both the position and momentum of a particle with absolute certainty.

Question 12

How many possible values of $$m_l$$ are there for $$l=2$$?

Accepted Answer

5

Question 13

Which of the following transitions in a hydrogen atom would emit the highest energy photon?

Accepted Answer

$$n=5 to$$ $$n=1$$

Question 14

Which quantum number is responsible for the orientation of an orbital in space?

Accepted Answer

Magnetic quantum number ($$m_l)$$

Question 15

What is the maximum number of electrons that can occupy a single orbital?

Accepted Answer

2

Question 16

Which of the following is a valid set of quantum numbers for a 4p orbital?

Accepted Answer

$$n=4, \ l=1, \ m_l=-1$$

Question 17

Which of the following best describes the meaning of the wavefunction $$\Psi in $$quantum mechanics?

Accepted Answer

$$\$$Psi^2$$ gives the probability density of finding an electron in a given region.

Question 18

How many d orbitals are present in a given shell?

Accepted Answer

5

Question 19

Which principle states that no two electrons in an atom can have the same set of four quantum numbers?

Accepted Answer

Pauli Exclusion Principle

Question 20

A hydrogen atom electron transitions from $$n=6 to$$ $$n=3. $$Calculate the energy of the photon emitted. ($$E_n = -2.18 	imes 10$$^{-18}$$ \frac{1}{n^2$} J)$$

Accepted Answer

$$4.00 	imes 10$$^{-19}$$ J

Quantum Mechanical Model of the Atom – Study Notes

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