Q: A hospital uses a green laser (wavelength = 532 nm) for eye surgery. Calculate the energy of one photon of this light. ($$h = 6.626 \times 10$$^{-34}$$ \ \mathrm{J \cdot s}$$, $$c = 3.00 \times 10^8$ \ \mathrm{m/s})$$

$$3.74 \times 10$$^{-19}$$ \ \mathrm{J}$$

Question 1

Which of the following statements best explains why quantum mechanics is foundational to chemistry?

Accepted Answer

It explains the periodic table and the chemical behavior of elements based on electron behavior.

Question 2

Why is it impossible to directly observe electrons in an atom without altering their behavior?

Accepted Answer

Observing electrons requires shining light on them, which changes their energy and position.

Question 3

Which property of light determines its color?

Accepted Answer

Wavelength or frequency

Question 4

A bright green laser and a dim red laser differ in which two properties?

Accepted Answer

They have different frequencies, and the green laser has a greater amplitude.

Question 5

Which of the following correctly arranges X-ray, visible, and infrared radiation in order of increasing wavelength?

Accepted Answer

X-ray \u003c visible \u003c infrared

Question 6

What is the relationship between the wavelength ($$\lambda) $$and frequency ($$
u) of $$electromagnetic waves?

Accepted Answer

They are inversely proportional.

Question 7

Which equation correctly relates the energy of a photon ($$E) to $$its wavelength ($$\lambda$$)?

Accepted Answer

$$E = \dfrac{hc}{\lambda}$$

Question 8

Which type of electromagnetic radiation has the highest energy and can potentially damage biological molecules?

Accepted Answer

Gamma rays

Question 9

When sodium ions are heated in a flame, they emit a characteristic yellow color. This phenomenon is best explained by:

Accepted Answer

Electrons jumping from higher to lower quantized energy levels, emitting photons of specific energy.

Question 10

According to Bohr’s model, what determines the energy of the photon emitted when an electron transitions between orbits?

Accepted Answer

The difference in energy between the two orbits.

Question 11

Which of the following best describes the emission spectrum of an element?

Accepted Answer

A unique pattern of discrete wavelengths specific to each element.

Question 12

A hospital uses a green laser (wavelength = 532 nm) for eye surgery. Calculate the energy of one photon of this light. ($$h = 6.626 	imes 10$$^{-34}$$ \ \mathrm{J \cdot s}$$, $$c = 3.00 	imes 10^8$ \ \mathrm{m/s})$$

Accepted Answer

$$3.74 	imes 10$$^{-19}$$ \ \mathrm{J}$$

Question 13

Which of the following is NOT a prediction or explanation provided by the quantum-mechanical model of the atom?

Accepted Answer

Why all elements have the same atomic radius.

Question 14

Which of the following statements about electromagnetic waves is correct?

Accepted Answer

The electric and magnetic fields oscillate in perpendicular planes.

Question 15

A student arranges the following types of electromagnetic radiation in order of increasing energy: infrared, visible, X-ray. Is this correct?

Accepted Answer

Yes, because energy increases as wavelength decreases.

Question 16

Which real-world application relies on the unique emission spectra of elements?

Accepted Answer

Identifying elements in distant stars using spectroscopy.

Question 17

If the frequency ($$
u) of a $$wave is $$6.0 	imes 10$$^{14}$$ \ \mathrm{Hz}$$, what is the wavelength ($$\lambda) in $$meters? ($$c = 3.00 	imes 10^8$ \ \mathrm{m/s})$$

Accepted Answer

$$5.0 	imes 10$$^{-7}$$ \ \mathrm{m}$$

Question 18

Which of the following best describes what happens when an atom absorbs energy?

Accepted Answer

Its electrons move to higher energy orbits and may later emit photons as they return to lower orbits.

Question 19

Which of the following is a consequence of the quantization of energy in the Bohr model?

Accepted Answer

Electrons can only occupy specific energy levels, leading to discrete spectral lines.

Quantum-Mechanical Model of the Atom: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard