Question 1

Which of the following statements best describes a chemical change?

Accepted Answer

A piece of iron rusting when exposed to air.

Question 2

A sample of gold has a mass of 96.5 g and a volume of 5.00 cm$$^3. $$What is the density of gold in g/cm$$^3$$?

Accepted Answer

$$19.3 g/cm$^3$$

Question 3

Which of the following is a heterogeneous mixture?

Accepted Answer

Salad with lettuce, tomatoes, and cucumbers

Question 4

How many significant figures are in the measurement $$0.00450 mL$$?

Accepted Answer

3

Question 5

Which of the following correctly expresses $$0.000215 in $$scientific notation?

Accepted Answer

$$2.15 	imes 10$$^{-4}$$

Question 6

A patient receives $$500 mL of $$saline solution. How many liters is this?

Accepted Answer

$$0.5 L$$

Question 7

Which of the following best describes an isotope?

Accepted Answer

Atoms of the same element with different numbers of neutrons.

Question 8

Which of the following elements is a noble gas?

Accepted Answer

Neon

Question 9

What is the number of valence electrons in a sulfur atom ($$Z = 16$$)?

Accepted Answer

6

Question 10

Which of the following best explains why metals are good conductors of electricity?

Accepted Answer

They have free-moving valence electrons.

Question 11

A neutral atom of magnesium has an atomic number of $$12$$ and a mass number of $$24. $$How many neutrons does it have?

Accepted Answer

$$12$$

Question 12

Which of the following is a chemical property?

Accepted Answer

Reactivity with acid

Question 13

Which of the following ions is isoelectronic with neon ($$Ne$$)?

Accepted Answer

$$F^-$$

Question 14

Which of the following best describes the trend in atomic radius across a period from left to right?

Accepted Answer

Atomic radius decreases.

Question 15

Which of the following is the correct formula for calcium chloride?

Accepted Answer

$$CaCl_2$$

Question 16

Which of the following best describes an ionic bond?

Accepted Answer

A bond formed by the transfer of electrons from a metal to a nonmetal.

Question 17

A 250 Calorie (Cal) snack bar provides how many joules of energy? ($$1 	ext{ Cal} = 4184 	ext{ J})$$

Accepted Answer

$$1,046,000 J$

Question 18

Which of the following statements about covalent compounds is true?

Accepted Answer

They are formed by sharing electrons between nonmetals.

Question 19

Which of the following is a correct Lewis symbol for the chloride ion ($$Cl^-$$)?

Accepted Answer

$$Cl$$ with 8 dots and a negative sign

Question 20

Which of the following best explains why noble gases are generally unreactive?

Accepted Answer

They have a full valence shell of electrons.

GOB Chemistry Study Guide: Measurement, Matter, Atomic Structure, and Chemical Bonding

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