Q: Which equation correctly expresses the energy change for an electron transition in the hydrogen atom, as shown in the image?

$$\Delta E = -2.18 \times 10$$^{-18}$$ \left( \frac{1}{n_f^2$} - \frac{1}{n_i^2$} \right) \, \text{J}$$

Q: A photon has a wavelength of $$4.00 \times 10$$^{-7}$$ m. What is the energy of this photon? (h = 6.626$$ \times $$10^{-34}$$ \, \text{J} \cdot \text{s}$$, c = 3.00$$ \times $$10^8$$ \, \text{m/s}$$)

$$4.97 \times 10$$^{-19}$$ \, \text{J}$$

Q: What is the de Broglie wavelength of an electron (mass $$= 9.11 \times 10$$^{-31}$$ \, \text{kg}) $$moving at $$2.00 \times 10^6$ \, \text{m/s}$$? ($$h = 6.626 \times 10$$^{-34}$$ \, \text{J} \cdot \text{s})$$

$$3.63 \times 10$$^{-10}$$ \, \text{m}$$

Q: A photon with energy $$5.0 \times 10$$^{-19}$$ \, \text{J}$$ strikes a metal with a binding energy of $$3.0 \times 10$$^{-19}$$ \, \text{J}. $$What is the kinetic energy of the ejected electron?

$$2.0 \times 10$$^{-19}$$ \, \text{J}$$

Question 1

Which of the following best describes the Law of Definite Proportions?

Accepted Answer

A compound always contains the same elements in the same proportion by mass.

Question 2

A sample contains 0.50 mol of NaCl. How many formula units of NaCl are present in the sample? (Avogadro's number $$= 6.022 	imes 10$$^{23}$$)

Accepted Answer

$$3.01 	imes 10$$^{23}$$

Question 3

Which equation correctly expresses the energy change for an electron transition in the hydrogen atom, as shown in the image?

Accepted Answer

$$\Delta E = -2.18 	imes 10$$^{-18}$$ \left( \frac{1}{n_f^2$} - \frac{1}{n_i^2$} ight) \, 	ext{J}$$

Question 4

A photon has a wavelength of $$4.00 	imes 10$$^{-7}$$ m. What is the energy of this photon? (h = 6.626$$ 	imes $$10^{-34}$$ \, 	ext{J} \cdot 	ext{s}$$, c = 3.00$$ 	imes $$10^8$$ \, 	ext{m/s}$$)

Accepted Answer

$$4.97 	imes 10$$^{-19}$$ \, 	ext{J}$$

Question 5

Which quantum number determines the shape of an atomic orbital?

Accepted Answer

The angular momentum quantum number $$l$$

Question 6

If an element has two naturally occurring isotopes with masses 10.0 amu (20%) and 11.0 amu (80%), what is the weighted average atomic mass?

Accepted Answer

10.8 amu

Question 7

Which of the following is a correct application of the Law of Multiple Proportions?

Accepted Answer

Two elements can combine in different ratios to form different compounds.

Question 8

What is the de Broglie wavelength of an electron (mass $$= 9.11 	imes 10$$^{-31}$$ \, 	ext{kg}) $$moving at $$2.00 	imes 10^6$ \, 	ext{m/s}$$? ($$h = 6.626 	imes 10$$^{-34}$$ \, 	ext{J} \cdot 	ext{s})$$

Accepted Answer

$$3.63 	imes 10$$^{-10}$$ \, 	ext{m}$$

Question 9

Which of the following best describes the Heisenberg Uncertainty Principle?

Accepted Answer

$$\Delta x \cdot m \Delta v \geq \frac{h}{4\pi}$$

Question 10

A sample of magnesium contains $$4.86 	imes 10$$^{24}$$ atoms. What is the mass of this sample? (Molar mass of Mg = 24.3$$ \, 	ext{g/mol}$$, Avogadro's number = 6.022$$ 	imes $$10^{23})$$

Accepted Answer

196 g

Question 11

Which of the following is NOT a criterion that defines a wave?

Accepted Answer

Density

Question 12

How many significant figures should be reported for the result of $$2.34 	imes 1.2$$?

Accepted Answer

2

Question 13

If $$n = 3$$, what are the possible values for the angular momentum quantum number $$l$$?

Accepted Answer

0, 1, 2

Question 14

A photon with energy $$5.0 	imes 10$$^{-19}$$ \, 	ext{J}$$ strikes a metal with a binding energy of $$3.0 	imes 10$$^{-19}$$ \, 	ext{J}. $$What is the kinetic energy of the ejected electron?

Accepted Answer

$$2.0 	imes 10$$^{-19}$$ \, 	ext{J}$$

Question 15

Which quantum numbers are needed to determine the energy of an electron in a multi-electron atom?

Accepted Answer

Principal quantum number $$n$$ and angular momentum quantum number $$l$$

Question 16

How many photons are in a pulse of light with total energy $$1.00 	imes 10$$^{-3}$$ \, 	ext{J} if $$each photon has energy $$2.48 	imes 10$$^{-19}$$ \, 	ext{J}$$?

Accepted Answer

$$4.03 	imes 10$$^{15}$$

Question 17

Which of the following conversion factors would you use to convert grams of a substance to number of atoms?

Accepted Answer

Grams to moles, then moles to atoms using Avogadro's number

General Chemistry Exam 1 Study Guide: Chapters E, 1, and 2

Guida di studio - Domande di pratica

Study guide - Flashcard