Question 1

A sample of a radioactive isotope has an initial mass of 80 mg. If the half-life of the isotope is 6 hours, how much of the isotope remains after 18 hours?

Accepted Answer

$$10\ \mathrm{mg}$$

Question 2

Which of the following statements best describes a chemical change?

Accepted Answer

Iron rusting in moist air.

Question 3

A patient receives 500 mL of a saline solution. If the density of the solution is $$1.05\ \mathrm{g/mL}$$, what is the mass of the solution administered?

Accepted Answer

$$525\ \mathrm{g}$$

Question 4

Which of the following is an example of an exact number?

Accepted Answer

The number of students in a classroom.

Question 5

Convert $$37.0\ ^\circ\mathrm{C} ($$normal human body temperature) to Kelvin.

Accepted Answer

$$310.2\ \mathrm{K}$$

Question 6

Which of the following nuclear equations is correctly balanced for the alpha decay of $$^{226}_{88}\mathrm{Ra}$$?

Accepted Answer

$$^{226}_{88}\mathrm{Ra} \$$rightarrow ^{222}$$_{86}\mathrm{Rn} $$+ ^{4}$$_{2}\mathrm{He}$$

Question 7

A nutrition label states that a snack contains 12 g of fat, 20 g of carbohydrate, and 4 g of protein. What is the total energy content of the snack in Calories (Cal)?

Accepted Answer

$$164\ \mathrm{Cal}$$

Question 8

Which of the following is a property of metals?

Accepted Answer

They are good conductors of heat and electricity.

Question 9

How many significant figures are in the measurement $$0.00450\ \mathrm{g}$$?

Accepted Answer

3

Question 10

Which of the following best describes a compound?

Accepted Answer

A substance composed of two or more elements chemically combined in a fixed ratio.

Question 11

A student measures the length of a metal rod as $$12.45\ \mathrm{cm}$$ and the width as $$1.2\ \mathrm{cm}. $$What is the area of the rod, reported with the correct number of significant figures?

Accepted Answer

$$15\ \mathrm{cm}^2$$

Question 12

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

Accepted Answer

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

Question 13

Which group on the periodic table contains the noble gases?

Accepted Answer

Group 18

Question 14

A sample of gold has a mass number of 197 and an atomic number of 79. How many neutrons are in this isotope?

Accepted Answer

118

Question 15

Which of the following is a physical property?

Accepted Answer

Melting point

Question 16

Convert $$2500\ \mathrm{mg} to $$grams using the appropriate conversion factor.

Accepted Answer

$$2.5\ \mathrm{g}$$

Question 17

Which of the following best describes the difference between kinetic and potential energy?

Accepted Answer

Kinetic energy is energy of motion; potential energy is stored energy.

Question 18

Which of the following is a beta particle?

Accepted Answer

An electron emitted from the nucleus during radioactive decay.

Question 19

A solution has a density of $$0.85\ \mathrm{g/mL}. $$What is the volume, in mL, of $$34\ \mathrm{g} of $$this solution?

Accepted Answer

$$40\ \mathrm{mL}$$

Question 20

Which of the following is a main group element?

Accepted Answer

Magnesium (Mg)

Foundations of Chemistry: Measurement, Matter, Atoms, and Nuclear Chemistry

Guida di studio - Domande di pratica

Study guide - Flashcard