Q: A photon has $$3.20 \times 10$$^{-19}$$\ \mathrm{J} of $$energy. What is its frequency in $$\mathrm{KHz}$$? (Use $$E = h\nu$$ and $$h = 6.626 \times 10$$^{-34}$$\ \mathrm{Js})$$

$$4.83 \times 10$$^{11}$$\ \mathrm{KHz}$$

Q: How many atoms of zinc are present in $$246.1\ \mathrm{g} of $$pure zinc? (Atomic mass of Zn $$= 65.38\ \mathrm{g/mol}$$, Avogadro's number $$= 6.022 \times 10$$^{23}$$\ \mathrm{atoms/mol})$$

$$2.27 \times 10$$^{24}$$ atoms

Q: Which equation is used to calculate the change in energy for an electron transition in hydrogen?

$$\Delta E = -2.178 \times 10$$^{-18}$$\left(\frac{1}{n_2$^2} - \frac{1}{n_1$^2}\right)$$

Question 1

Morphine, with the formula $$\mathrm{C$$_{17}$$H_{19}NO_3$}$$, is used as a pain medication. Which classification best describes morphine?

Accepted Answer

Compound

Question 2

A poppy flower contains morphine, water, and other substances. Which classification best describes the poppy flower?

Accepted Answer

Heterogeneous mixture

Question 3

Which of the following is an extrinsic property of a sample of morphine?

Accepted Answer

The sample has a mass of 18.6 g

Question 4

Rhodium-101 is an isotope of rhodium. How many neutrons does rhodium-101 have?

Accepted Answer

$$56$$

Question 5

An element X has $$42$$ protons and $$54$$ neutrons. What is the full chemical symbol for the isotope?

Accepted Answer

$$^{96}_{42}\mathrm{Mo}$$

Question 6

Which transition in a hydrogen atom corresponds to the absorption of the shortest wavelength photon?

Accepted Answer

$$n=4\rightarrow n=1$$

Question 7

Which statement about Rutherford’s gold foil experiment is correct?

Accepted Answer

Alpha particles were found to be deflected at very large angles, which was consistent with encountering dense positive charge, not diffuse charge.

Question 8

Which statement is part of the nuclear model of the atom that arose out of Rutherford’s gold foil experiment?

Accepted Answer

Most of the mass is located in a very small region at the center of the atom called the nucleus.

Question 9

Mercury melts at $$234.3\ \mathrm{K}$$ and boils at $$629.9\ \mathrm{K}. $$What is the physical state of mercury at $$204\ ^\circ\mathrm{F}$$? (Use $$T_K = (T_F - 32) 	imes \frac{5}{9} + 273.15)$$

Accepted Answer

Solid

Question 10

When $$3.000\ \mathrm{g} of $$carbon dioxide is decomposed, $$0.819\ \mathrm{g} of $$carbon and $$2.181\ \mathrm{g} of $$oxygen are obtained, regardless of the source. Which fundamental law(s) does this experiment illustrate?

Accepted Answer

Law of definite proportions and conservation of mass

Question 11

A photon has $$3.20 	imes 10$$^{-19}$$\ \mathrm{J} of $$energy. What is its frequency in $$\mathrm{KHz}$$? (Use $$E = h
u$$ and $$h = 6.626 	imes 10$$^{-34}$$\ \mathrm{Js})$$

Accepted Answer

$$4.83 	imes 10$$^{11}$$\ \mathrm{KHz}$$

Question 12

An electron in a hydrogen atom is excited from $$n=1 to$$ $$n=2. $$Does the electron emit or absorb energy during this process?

Accepted Answer

Absorb

Question 13

What is the wavelength (in nm) of the photon required for the $$n=1 to$$ $$n=2$$ transition in hydrogen? (Use $$\Delta E = -2.178 	imes 10$$^{-18}$$\left(\frac{1}{n_2$^2} - \frac{1}{n_1$^2}ight)$$, $$E = h
u$$, $$c = \lambda
u)$$

Accepted Answer

$$121.6\ \mathrm{nm}$$

Question 14

In what region of the electromagnetic spectrum does the $$n=1 to$$ $$n=2$$ transition in hydrogen occur?

Accepted Answer

Ultraviolet

Question 15

Would the transition from $$n=1 to$$ $$n=3$$ give a higher or lower frequency photon compared to the $$n=1 to$$ $$n=2$$ transition?

Accepted Answer

Lower frequency

Question 16

Which type of glassware is least precise for measuring volume?

Accepted Answer

Graduated cylinder

Question 17

How many atoms of zinc are present in $$246.1\ \mathrm{g} of $$pure zinc? (Atomic mass of Zn $$= 65.38\ \mathrm{g/mol}$$, Avogadro's number $$= 6.022 	imes 10$$^{23}$$\ \mathrm{atoms/mol})$$

Accepted Answer

$$2.27 	imes 10$$^{24}$$ atoms

Question 18

Which equation correctly relates energy and frequency for a photon?

Accepted Answer

$$E = h
u$$

Question 19

Which equation is used to calculate the change in energy for an electron transition in hydrogen?

Accepted Answer

$$\Delta E = -2.178 	imes 10$$^{-18}$$\left(\frac{1}{n_2$^2} - \frac{1}{n_1$^2}ight)$$

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