Q: Which of the following is a correct conversion factor for converting grams to moles?

$$\frac{1\ \mathrm{mol}}{\text{molar mass in g}}$$

Question 1

Which of the following is the correct order of steps in the scientific method?

Accepted Answer

Observation, Hypothesis, Experiment, Analysis, Conclusion

Question 2

How many significant figures are in the measurement 0.00450?

Accepted Answer

3

Question 3

A student measures the mass of a sample as 12.30 g and its volume as 4.1 mL. What is the density of the sample, and how many significant figures should the answer have?

Accepted Answer

$$3.0\ \mathrm{g/mL}$$, 2 significant figures

Question 4

Which of the following is NOT a component of an atom?

Accepted Answer

Photon

Question 5

Which isotope has 6 protons, 8 neutrons, and 6 electrons?

Accepted Answer

$$^{14}\mathrm{C}$$

Question 6

Calculate the average atomic mass of chlorine if $$75.77\% of $$chlorine atoms are $$^{35}\mathrm{Cl} ($$mass = $$34.969\ \mathrm{amu}) $$and $$24.23\%$$ are $$^{37}\mathrm{Cl} ($$mass = $$36.966\ \mathrm{amu}).$$

Accepted Answer

$$35.45\ \mathrm{amu}$$

Question 7

Which of the following electron configurations represents a neutral atom of potassium ($$Z=19$$)?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^6$$\ $$3s^2$$\ $$3p^6$$\ $$4s^1$$

Question 8

What is the quantum number $$l$$ for a 3p electron?

Accepted Answer

$$l = 1$$

Question 9

Which element has the electron configuration $$1s^2$$\ $$2s^2$$\ $$2p^6$$\ $$3s^2$$\ $$3p^6$$\ $$4s^2$$?

Accepted Answer

Calcium

Question 10

A sample contains 60.0 g of NaCl. What is the percent by mass of sodium in NaCl? ($$\mathrm{Na} = 22.99\ \mathrm{g/mol}$$, $$\mathrm{Cl} = 35.45\ \mathrm{g/mol})$$

Accepted Answer

$$37.7\%$$

Question 11

Convert $$25.0\ ^\circ\mathrm{C} to $$Kelvin.

Accepted Answer

$$298.2\ \mathrm{K}$$

Question 12

Which of the following is the correct electron configuration for a fluoride ion ($$\mathrm{F}^-$$)?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^6$$

Question 13

Which element has a full outer shell in its ground state electron configuration?

Accepted Answer

Neon

Question 14

A compound contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. What is the empirical formula?

Accepted Answer

$$\mathrm{CH}_2\mathrm{O}$$

Question 15

Which of the following is a correct conversion factor for converting grams to moles?

Accepted Answer

$$\frac{1\ \mathrm{mol}}{	ext{molar mass in g}}$$

Question 16

Which of the following statements about isotopes is TRUE?

Accepted Answer

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

Question 17

Which element has the symbol 'Fe'?

Accepted Answer

Iron

Question 18

A sample of magnesium contains $$3.01 	imes 10$$^{22}$$ atoms. How many moles of magnesium are present?

Accepted Answer

$$0.0500\ \mathrm{mol}$$

Question 19

Which of the following is the correct electron configuration for a neutral carbon atom?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^2$$

Introduction to Chemistry: Atomic Structure, Significant Figures, and Electron Configuration

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