Question 1

Which of the following statements correctly describes the difference between a physical change and a chemical change?

Accepted Answer

A chemical change results in the formation of new substances, while a physical change does not.

Question 2

A student measures the mass of a metal sample as $$12.34\ \mathrm{g}$$ and its volume as $$4.2\ \mathrm{mL}. $$What is the density of the metal, reported with the correct number of significant figures?

Accepted Answer

$$2.9\ \mathrm{g/mL}$$

Question 3

Which of the following elements is a nonmetal located in period 2 of the periodic table?

Accepted Answer

Oxygen ($$\mathrm{O})$$

Question 4

How many significant figures are in the measurement $$0.004560\ \mathrm{g}$$?

Accepted Answer

4

Question 5

Which of the following correctly represents the isotope of chlorine with 18 neutrons?

Accepted Answer

$$\$$displaystyle ^{35}$$_{17}\mathrm{Cl}$$

Question 6

A patient is prescribed a medication at a dosage of $$5.0\ \mathrm{mg/kg}$$ body weight. If the patient weighs $$70.0\ \mathrm{kg}$$, how many milligrams of medication should be administered?

Accepted Answer

$$350\ \mathrm{mg}$$

Question 7

Which of the following best describes the octet rule?

Accepted Answer

Atoms tend to gain, lose, or share electrons to achieve eight electrons in their outermost shell.

Question 8

What is the correct number of significant figures in the result of the following calculation: $$3.45	imes 2.1$$?

Accepted Answer

2

Question 9

Which of the following ions is formed when a magnesium atom achieves a noble gas configuration?

Accepted Answer

$$\mathrm{Mg}^{2+}$$

Question 10

A graduated cylinder contains $$25.0\ \mathrm{mL} of $$water. After a metal object is submerged, the water level rises to $$32.5\ \mathrm{mL}. If $$the mass of the object is $$60.0\ \mathrm{g}$$, what is its density?

Accepted Answer

$$6.7\ \mathrm{g/mL}$$

Question 11

Which of the following is the correct scientific notation for the number $$0.00056$$?

Accepted Answer

$$5.6 	imes 10$$^{-4}$$

Question 12

Which of the following best describes an isotope?

Accepted Answer

Atoms of the same element with different numbers of neutrons.

Question 13

Which of the following is the correct conversion factor for converting from milligrams to grams?

Accepted Answer

$$1\ \mathrm{mg} = 0.001\ \mathrm{g}$$

Question 14

Which of the following elements is in Group 2A and is classified as a metal?

Accepted Answer

Calcium ($$\mathrm{Ca})$$

Question 15

A chemical reaction is represented as $$2\mathrm{H}_2 + \mathrm{O}_2 \rightarrow 2\mathrm{H}_2\mathrm{O}. $$Which are the reactants in this reaction?

Accepted Answer

$$2\mathrm{H}_2$$ and $$\mathrm{O}_2$$

Question 16

How many atoms of oxygen are present in one formula unit of $$\mathrm{Al}_2(\mathrm{SO}_4)_3$$?

Accepted Answer

12

Question 17

Which of the following best describes a cation?

Accepted Answer

An atom that has lost one or more electrons and has a positive charge.

Question 18

A sample contains $$3.0\ \mathrm{g} of a $$substance with a density of $$0.60\ \mathrm{g/mL}. $$What is the volume of the sample?

Accepted Answer

$$5.0\ \mathrm{mL}$$

Question 19

Which of the following best describes the number of valence electrons in a phosphorus atom ($$\mathrm{P}$$, atomic number 15)?

Accepted Answer

5

Question 20

Which of the following shows the correct symbolic notation for an atom with 11 protons, 12 neutrons, and 10 electrons?

Accepted Answer

$$\$$displaystyle ^{23}$$_{11}\mathrm{Na}^{+}$$

CHEM 1050 Exam 1 Study Guide: Matter, Measurement, Atoms, and Compounds

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