Q: A laser pulse emits $$55.0 \muJ of $$energy at a wavelength of $$675 nm. $$How many photons are in the pulse? ($$h = 6.626 \times 10$$^{-34}$$ J·s, c = 3.00$$ \times $$10^8 m/s)$$

$$5.62 \times 10$$^{14}$$ photons

Question 1

Which of the following statements best describes the relationship between wavelength ($$\lambda) $$and frequency ($$
u) of $$electromagnetic radiation?

Accepted Answer

They are inversely proportional; as wavelength increases, frequency decreases.

Question 2

A photon of light has a frequency of $$7.50 	imes 10$$^{14}$$ Hz. What is its wavelength in meters? (Speed of light c = 3.00$$ 	imes $$10^8 m/s)$$

Accepted Answer

$$3.99 	imes 10$$^{-7}$$ m

Question 3

Which equation correctly relates the energy of a photon ($$E_{photon}) to $$its frequency ($$
u$$)?

Accepted Answer

$$E_{photon} = h 
u$$

Question 4

A laser pulse emits $$55.0 \muJ of $$energy at a wavelength of $$675 nm. $$How many photons are in the pulse? ($$h = 6.626 	imes 10$$^{-34}$$ J·s, c = 3.00$$ 	imes $$10^8 m/s)$$

Accepted Answer

$$5.62 	imes 10$$^{14}$$ photons

Question 5

Which color of visible light has the highest energy per photon?

Accepted Answer

Violet

Question 6

Which principle states that it is impossible to exactly measure both the position and momentum of an electron?

Accepted Answer

Heisenberg uncertainty principle

Question 7

What is the maximum number of electrons that can occupy the $$d$$ sublevel in a single energy level?

Accepted Answer

10

Question 8

Which quantum number determines the shape of an orbital?

Accepted Answer

Angular momentum quantum number ($$l)$$

Question 9

Which electron configuration represents the ground state of sodium ion ($$Na^+$$)?

Accepted Answer

$$1s^2$$ $$2s^2$$ $$2p^6$$

Question 10

Which rule states that electrons fill the lowest energy orbitals first?

Accepted Answer

Aufbau principle

Question 11

Which of the following is an isoelectronic pair?

Accepted Answer

S$$^{2-}$$ and Cl$$^{-}$$

Question 12

Which element has the following condensed electron configuration: $$[Ar] 4s^2$ 3d^7$?

Accepted Answer

Cobalt

Question 13

Which of the following best explains why transition metals often have unexpected electron configurations?

Accepted Answer

They are stabilized by filled or half-filled energy sublevels.

Question 14

What is the noble gas configuration for selenium (Se, atomic number 34)?

Accepted Answer

$$[Ar] 4s^2$ 3d$$^{10}$$ 4p^4$

Question 15

Which quantum numbers are required to uniquely identify an electron in an atom?

Accepted Answer

n, l, m_l, m_s

Question 16

Which of the following best describes the difference between the Bohr model and the quantum model of the atom?

Accepted Answer

The Bohr model treats electrons as particles in fixed orbits, while the quantum model describes electrons as waves occupying regions of probability.

Question 17

Which orbital letter designation corresponds to an angular momentum quantum number ($$l) of 2$$?

Accepted Answer

d

Question 18

How many possible values of the magnetic quantum number ($$m_l) $$are there for a $$p$$ orbital?

Accepted Answer

3

Question 19

Which of the following statements about valence electrons is correct?

Accepted Answer

Valence electrons are responsible for the chemical behavior of an element.

Quantum Mechanics and Electronic Structure: Study Notes for General Chemistry

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