Q: A laser pointer emits red light with a wavelength of $$\lambda = 650\ \mathrm{nm}. $$What is the frequency of this light? (Speed of light $$c = 3.00 \times 10^8$\ \mathrm{m/s})$$

$$4.62 \times 10$$^{14}$$\ \mathrm{Hz}$$

Q: According to the Bohr model, what is the energy of a photon emitted when an electron in a hydrogen atom transitions from $$n=3 to$$ $$n=2$$? (Use $$E_n = -2.18 \times 10$$^{-18}$$\ \mathrm{J} / n^2$)

$$3.03 \times 10$$^{-19}$$\ \mathrm{J}$$

Q: A sodium street lamp emits yellow light at $$\lambda = 589\ \mathrm{nm}. $$What is the energy of one photon of this light? ($$h = 6.63 \times 10$$^{-34}$$\ \mathrm{J \cdot s}$$, $$c = 3.00 \times 10^8$\ \mathrm{m/s})$$

$$3.38 \times 10$$^{-19}$$\ \mathrm{J}$$

Question 1

A laser pointer emits red light with a wavelength of $$\lambda = 650\ \mathrm{nm}. $$What is the frequency of this light? (Speed of light $$c = 3.00 	imes 10^8$\ \mathrm{m/s})$$

Accepted Answer

$$4.62 	imes 10$$^{14}$$\ \mathrm{Hz}$$

Question 2

Which of the following best describes the photoelectric effect?

Accepted Answer

Electrons are ejected from a metal surface when it is exposed to light of sufficient frequency.

Question 3

Which experiment provided direct evidence for the wave nature of electrons?

Accepted Answer

The double-slit experiment with electrons.

Question 4

According to the Bohr model, what is the energy of a photon emitted when an electron in a hydrogen atom transitions from $$n=3 to$$ $$n=2$$? (Use $$E_n = -2.18 	imes 10$$^{-18}$$\ \mathrm{J} / n^2$)

Accepted Answer

$$3.03 	imes 10$$^{-19}$$\ \mathrm{J}$$

Question 5

Which quantum number determines the shape of an atomic orbital?

Accepted Answer

The angular momentum quantum number $$l$$

Question 6

What is the wavelength of an electron (in meters) moving at $$2.0 	imes 10^6$\ \mathrm{m/s}$$? (Use $$m_e = 9.11 	imes 10$$^{-31}$$\ \mathrm{kg}$$, $$h = 6.63 	imes 10$$^{-34}$$\ \mathrm{J \cdot s})$$

Accepted Answer

$$3.64 	imes 10$$^{-10}$$

Question 7

Which statement about Heisenberg's uncertainty principle is correct?

Accepted Answer

It states that the more precisely the position of a particle is known, the less precisely its momentum can be known.

Question 8

Which of the following best describes constructive interference?

Accepted Answer

Two waves combine to produce a wave with greater amplitude.

Question 9

How many radial nodes are present in a $$3p$$ orbital?

Accepted Answer

1

Question 10

Which of the following is a correct statement about the probability density function for an atomic orbital?

Accepted Answer

It gives the probability of finding an electron at a particular point in space.

Question 11

Which quantum numbers are needed to uniquely describe an electron in an atom?

Accepted Answer

Principal quantum number $$n$$, angular momentum quantum number $$l$$, magnetic quantum number $$m_l$$, and spin quantum number $$m_s$$

Question 12

A sodium street lamp emits yellow light at $$\lambda = 589\ \mathrm{nm}. $$What is the energy of one photon of this light? ($$h = 6.63 	imes 10$$^{-34}$$\ \mathrm{J \cdot s}$$, $$c = 3.00 	imes 10^8$\ \mathrm{m/s})$$

Accepted Answer

$$3.38 	imes 10$$^{-19}$$\ \mathrm{J}$$

Question 13

Which of the following statements about atomic emission spectra is correct?

Accepted Answer

Each element has a unique emission spectrum because its electrons occupy specific energy levels.

Question 14

Which set of quantum numbers is not allowed for an electron in an atom?

Accepted Answer

$$n=2,\ l=2,\ m_l=0,\ m_s=+\frac{1}{2}$$

Question 15

Which of the following best explains why X-rays have higher energy than visible light?

Accepted Answer

X-rays have a higher frequency than visible light.

Question 16

Which orbital has the greatest number of angular nodes?

Accepted Answer

$$4d$$

Question 17

A hospital uses ultraviolet (UV) light to sterilize equipment. Which property of UV light makes it effective for this purpose?

Accepted Answer

UV light has enough energy to break chemical bonds in microorganisms.

Question 18

Which of the following statements about the Schrödinger equation is correct?

Accepted Answer

It describes the allowed energies and wave functions of electrons in atoms.

Question 19

Which of the following best describes the phase of an atomic orbital?

Accepted Answer

It refers to the sign (positive or negative) of the wave function in different regions of space.

Question 20

Which of the following is a correct statement about the relationship between wavelength, frequency, and the speed of light?

Accepted Answer

$$c = \lambda 
u$$

General Chemisrty Study - Chapter 2

Guida di studio - Domande di pratica

Study guide - Flashcard