Q: What is the energy of a photon with a wavelength equal to 405 nm?

$$E = \dfrac{hc}{\lambda} = \dfrac{6.626 \times 10$$^{-34}$$\ \mathrm{J\cdot s} \times 3.00 \times 10^8$\ \mathrm{m/s}}{405 \times 10$$^{-9}$$\ \mathrm{m}} \approx 4.91 \times 10$$^{-19}$$\ \mathrm{J}$$

Question 1

Which color of visible light has photons with the lowest energy?

Accepted Answer

Red (X = 650 nm)

Question 2

Which of the following sets of quantum numbers is allowed for an electron in an atom?

Accepted Answer

$$n = 3, l = 2, m_l = -2, m_s = +\frac{1}{2}$$

Question 3

Forming chemical bonds ______ energy, and breaking chemical bonds ______ energy.

Accepted Answer

releases; requires

Question 4

Which is the best Lewis structure for XeO$$_2$$ based on the electronegativity principle?

Accepted Answer

$$\mathrm{O{-}Xe{-}O}$$

Question 5

Which of the following covalent bonds between carbon atoms is the longest?

Accepted Answer

C-C

Question 6

Which atom in the 3rd period of the periodic table has the largest atomic radius?

Accepted Answer

Sodium (Na)

Question 7

When electricity was sent through a pickle during class, light was given off. The light provided evidence that what element was present in the pickle?

Accepted Answer

Sodium

Question 8

In the Lewis structure for NCl$$_3$$, the nitrogen atom has how many bond pairs and lone pairs?

Accepted Answer

3 bond pairs, 1 lone pair

Question 9

Which of the following correctly matches the orbital shapes for an s-orbital, p-orbital, and d-orbital?

Accepted Answer

s-orbital: spherical; p-orbital: dumbbell; d-orbital: cloverleaf

Question 10

Which element has the electronic configuration $$[\mathrm{Kr}]\ 5s^2$\ 4d$$^{10}$$\ 5p^4$?

Accepted Answer

Tellurium (Te)

Question 11

Which of the following atoms has the highest first ionization energy?

Accepted Answer

Oxygen (O)

Question 12

How many core electrons does an atom of phosphorus have?

Accepted Answer

10

Question 13

How many electrons are in the 3p subshell of a sulfur atom?

Accepted Answer

4

Question 14

What is the energy of a photon with a wavelength equal to 405 nm?

Accepted Answer

$$E = \dfrac{hc}{\lambda} = \dfrac{6.626 	imes 10$$^{-34}$$\ \mathrm{J\cdot s} 	imes 3.00 	imes 10^8$\ \mathrm{m/s}}{405 	imes 10$$^{-9}$$\ \mathrm{m}} \approx 4.91 	imes 10$$^{-19}$$\ \mathrm{J}$$

Question 15

An electron in a hydrogen atom drops from $$n = 5 to$$ $$n = 2$$, emitting a photon in the process. What is the wavelength of the emitted photon?

Accepted Answer

$$\lambda = \dfrac{hc}{E} = \dfrac{hc}{R_H \left( \dfrac{1}{2^2$} - \dfrac{1}{5^2$} \right)} \approx 434\ \mathrm{nm}$$

Question 16

What is the formal charge on the boron and oxygen atoms in the borate ion, $$\mathrm{BO_3$^{3-}}$$?

Accepted Answer

Boron: 0; Oxygen: -1

Question 17

Which quantum number determines the shape of an orbital?

Accepted Answer

Azimuthal quantum number ($$l)$$

Question 18

Which quantum number determines the spatial orientation of an orbital?

Accepted Answer

Magnetic quantum number ($$m_l)$$

Question 19

Which quantum number determines the spin of an electron?

Accepted Answer

Spin quantum number ($$m_s)$$

General Chemistry Exam Review: Atomic Structure, Bonding, and Periodic Trends

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