Q: A photon has a wavelength of $$500\ \mathrm{nm}. $$What is its frequency? ($$c = 3.00 \times 10^8$\ \mathrm{m/s})$$

$$6.00 \times 10$$^{14}$$\ \mathrm{Hz}$$

Question 1

Which of the following best describes the difference between a physical property and a chemical property?

Accepted Answer

A physical property can be measured without changing the substance's identity, while a chemical property describes the substance's ability to undergo chemical changes.

Question 2

Which of the following is an example of an extensive property?

Accepted Answer

Mass

Question 3

A student measures the mass of a sample as 12.345 g, 12.346 g, and 12.344 g in three trials. The true mass is 12.400 g. Which statement best describes the measurements?

Accepted Answer

The measurements are precise but not accurate.

Question 4

Which of the following correctly rounds the number 0.00456789 to three significant figures?

Accepted Answer

0.00457

Question 5

Which equation correctly relates density ($$d$$), mass ($$m$$), and volume ($$V$$)?

Accepted Answer

$$m = d 	imes V$$

Question 6

A sample has a mass of 25.0 g and a volume of 10.0 mL. What is its density, and how many significant figures should the answer have?

Accepted Answer

2.50 g/mL, three significant figures

Question 7

Which of the following is the correct symbol for an atom of chlorine-37?

Accepted Answer

$$^{37}_{17}\mathrm{Cl}$$

Question 8

Which statement about isotopes is correct?

Accepted Answer

Isotopes have the same number of protons but different numbers of neutrons.

Question 9

Calculate the number of moles in 18.0 g of water ($$\mathrm{H}_2\mathrm{O}$$). ($$M_{\mathrm{H}_2$$\mathrm{O}} = 18.0\ \mathrm{g/mol}$$)

Accepted Answer

1.0 mol

Question 10

Which of the following is the correct molecular formula for glucose?

Accepted Answer

$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6$$

Question 11

Which of the following elements is a metalloid?

Accepted Answer

Silicon ($$\mathrm{Si})$$

Question 12

What is the most common charge for elements in Group 17 (halogens) when forming ions?

Accepted Answer

$$-1$$

Question 13

Which quantum number determines the shape of an orbital?

Accepted Answer

Angular momentum quantum number ($$l)$$

Question 14

How many electrons can occupy a single orbital according to the Pauli exclusion principle?

Accepted Answer

Two, with opposite spins

Question 15

Which of the following best describes the difference between absorption and emission spectra?

Accepted Answer

Absorption spectra show dark lines where light is absorbed, while emission spectra show bright lines where light is emitted.

Question 16

Which equation correctly relates the energy ($$E) of $$electromagnetic radiation to its frequency ($$
u$$)?

Accepted Answer

$$E = h 
u$$

Question 17

A photon has a wavelength of $$500\ \mathrm{nm}. $$What is its frequency? ($$c = 3.00 	imes 10^8$\ \mathrm{m/s})$$

Accepted Answer

$$6.00 	imes 10$$^{14}$$\ \mathrm{Hz}$$

Question 18

Which of the following is a correct set of quantum numbers for an electron in a $$3p$$ orbital?

Accepted Answer

$$n=3,\ l=1,\ m_l=0,\ m_s=+\frac{1}{2}$$

Question 19

Which statement best explains why transition metals often have multiple oxidation states?

Accepted Answer

Their $$d$$ and $$s$$ electrons are close in energy, allowing for variable electron loss.

Question 20

Which of the following is a correct condensed structural formula for ethanol?

Accepted Answer

$$\mathrm{CH}_3\mathrm{CH}_2\mathrm{OH}$$

General Chemistry: Fundamental Concepts and Atomic Structure

Guida di studio - Domande di pratica

Study guide - Flashcard