Q: A photon of ultraviolet light has a wavelength of $$200\ \text{nm}. $$What is the energy of this photon in joules? (Use $$h = 6.626 \times 10$$^{-34}$$\ \text{J}\cdot\text{s}$$ and $$c = 3.00 \times 10^8$\ \text{m/s})$$

$$9.94 \times 10$$^{-19}$$\ \text{J}$$

Question 1

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

Accepted Answer

The speed of light is equal to the product of wavelength and frequency: $$c = \lambda 
u$$

Question 2

A photon of ultraviolet light has a wavelength of $$200\ 	ext{nm}. $$What is the energy of this photon in joules? (Use $$h = 6.626 	imes 10$$^{-34}$$\ 	ext{J}\cdot	ext{s}$$ and $$c = 3.00 	imes 10^8$\ 	ext{m/s})$$

Accepted Answer

$$9.94 	imes 10$$^{-19}$$\ 	ext{J}$$

Question 3

Which quantum number determines the shape of an atomic orbital?

Accepted Answer

The azimuthal quantum number $$l$$

Question 4

According to the Heisenberg Uncertainty Principle, which of the following is true?

Accepted Answer

It is impossible to simultaneously know both the exact position and exact momentum of an electron.

Question 5

Which electron configuration represents a paramagnetic ion?

Accepted Answer

[Ar] $$3d^5$$

Question 6

Which element has the highest effective nuclear charge ($$Z_{	ext{eff}}) $$for its valence electrons?

Accepted Answer

Fluorine ($$F)$$

Question 7

Which of the following ions has the smallest ionic radius in the isoelectronic series: $$O^{2-}$$, $$F^-$$, $$Na^+$$, $$Mg^{2+}$$?

Accepted Answer

$$Mg^{2+}$$

Question 8

Which of the following statements about electron affinity is correct?

Accepted Answer

A negative electron affinity indicates that energy is released when an atom gains an electron.

Question 9

Which of the following best explains why alkali metals are highly reactive?

Accepted Answer

They have a single valence electron that is easily removed, resulting in a low ionization energy.

Question 10

Which of the following Lewis structures correctly represents the nitrate ion ($$NO_3$$^-$$) with formal charges?

Accepted Answer

One oxygen atom has a formal charge of $$-1$$, and the nitrogen atom has a formal charge of $$+1.$$

Question 11

Which of the following compounds has the highest lattice energy?

Accepted Answer

$$MgO$$

Question 12

Which of the following molecules violates the octet rule due to an expanded octet?

Accepted Answer

$$SF_6$$

Question 13

Which bond is the shortest and strongest among the following?

Accepted Answer

A triple bond between two nitrogen atoms ($$N \equiv N)$$

Question 14

Which molecule has a polar bond but is overall nonpolar?

Accepted Answer

$$CO_2$$

Question 15

What is the molecular geometry of $$SF_4$$ according to VSEPR theory?

Accepted Answer

See-saw

Question 16

How many sigma ($$\sigma) $$and pi ($$\pi) $$bonds are present in ethylene ($$C_2H_4$$)?

Accepted Answer

5 $$\sigma$$ bonds and 1 $$\pi$$ bond

Question 17

According to Molecular Orbital Theory, what is the bond order of $$O_2$$?

Accepted Answer

2

Question 18

Which of the following molecules is paramagnetic according to Molecular Orbital Theory?

Accepted Answer

$$O_2$$

Question 19

A spectrophotometry experiment measures the absorbance of a solution at a specific wavelength. Which equation relates absorbance ($$A$$), molar absorptivity ($$\epsilon$$), path length ($$l$$), and concentration ($$c$$)?

Accepted Answer

$$A = \epsilon l c$$

Question 20

Using the Born-Haber cycle, which step is NOT included in the calculation of lattice energy for an ionic compound?

Accepted Answer

Condensation of the gaseous ions

General Chemistry Study Guide: Quantum Mechanics, Periodic Properties, and Chemical Bonding

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