Question 1

Which of the following best describes a homogeneous mixture?

Accepted Answer

A mixture in which the composition is uniform throughout, such as salt water.

Question 2

Which subatomic particle has a relative mass of approximately 1 amu and is found in the nucleus of an atom?

Accepted Answer

Proton

Question 3

Which of the following changes is a chemical change?

Accepted Answer

Burning a piece of paper

Question 4

Which group on the periodic table contains the noble gases?

Accepted Answer

Group 8A

Question 5

Convert $$3.45 	imes 10^4$ mg to grams using dimensional analysis.

Accepted Answer

$$34.5 g$$

Question 6

A sample has a mass of $$12.0 g $$and a volume of $$8.0 mL. $$What is its density?

Accepted Answer

$$1.5 g/mL$$

Question 7

Which of the following numbers has three significant figures?

Accepted Answer

$$0.0405$$

Question 8

Which of the following is the correct electron configuration for magnesium ($$Z=12$$)?

Accepted Answer

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

Question 9

Which of the following pairs are isotopes of each other?

Accepted Answer

$$^{14}_{6}\mathrm{C}$$\ and\ $$^{12}_{6}\mathrm{C}$$

Question 10

Which element has the highest ionization energy among the following?

Accepted Answer

Neon ($$\mathrm{Ne})$$

Question 11

Which of the following represents a beta decay process?

Accepted Answer

$$^{14}_{6}\mathrm{C} \rightarrow\ ^{14}_{7}\mathrm{N} + \ ^{0}_{-1}\beta$$

Question 12

A radioactive isotope has a half-life of $$4$$ hours. If you start with $$80 mg$$, how much remains after $$12$$ hours?

Accepted Answer

$$10 mg$$

Question 13

Which unit is used to measure the activity (rate of decay) of a radioactive sample?

Accepted Answer

Curie (Ci)

Question 14

Which isotope is most commonly used in PET scans?

Accepted Answer

$$^{18}\mathrm{F}$$

Question 15

Which of the following best describes nuclear fission?

Accepted Answer

A heavy nucleus splits into two lighter nuclei, releasing energy and neutrons.

Question 16

How many valence electrons does phosphorus ($$Z=15) $$have?

Accepted Answer

5

Question 17

Which of the following elements is most likely to form a $$2+$$ ion?

Accepted Answer

Magnesium ($$\mathrm{Mg})$$

Question 18

What is the charge on the copper ion in $$\mathrm{CuCl}_2$$?

Accepted Answer

$$2+$$

Question 19

Which of the following is the correct formula for the ionic compound formed between aluminum and oxygen?

Accepted Answer

$$\mathrm{Al}_2\mathrm{O}_3$$

Question 20

A patient receives a radiation dose of $$0.050 Gy. $$How many rads is this?

Accepted Answer

$$5.0$$ rads

Chem 101 Exam 1 Study Guide: Chapters 1–5.3 (Atoms, Matter, Measurement, Nuclear Chemistry, and Ionic Compounds)

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