Q: What is the correct formula to convert a temperature from Fahrenheit to Celsius?

$$T_C = \\frac{5}{9} (T_F - 32)$$

Question 1

Which of the following best describes a scientific theory?

Accepted Answer

A well-substantiated, comprehensive explanation of particular aspects of nature that can be modified if new data arise.

Question 2

Which of the following is an example of an extensive property?

Accepted Answer

Mass

Question 3

A student measures the mass of a sample as 12.30 g and its volume as 4.10 mL. What is the density of the sample, reported with the correct number of significant figures?

Accepted Answer

$$3.00 \ \mathrm{g/mL}$$

Question 4

Which statement about Dalton’s atomic theory is NOT correct according to modern understanding?

Accepted Answer

Atoms of a given element are identical in mass and properties.

Question 5

Which of the following is a heterogeneous mixture?

Accepted Answer

Chocolate chip cookies

Question 6

Which of the following best describes the law of conservation of matter?

Accepted Answer

The total quantity of matter present remains constant when matter converts from one type to another.

Question 7

Which of the following is a physical change?

Accepted Answer

Melting of ice

Question 8

A sample of an element contains atoms with 20 protons, 20 neutrons, and 18 electrons. What is the charge of this ion?

Accepted Answer

$$2+$$

Question 9

Which scientist is credited with discovering the electron using the cathode ray tube experiment?

Accepted Answer

J.J. Thomson

Question 10

What is the correct formula to convert a temperature from Fahrenheit to Celsius?

Accepted Answer

$$T_C = \frac{5}{9} (T_F - 32)$$

Question 11

Which of the following statements about isotopes is correct?

Accepted Answer

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

Question 12

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 13

Which of the following is a chemical property?

Accepted Answer

Flammability

Question 14

Which prefix and symbol represent $$10^{-9}$$?

Accepted Answer

nano, n

Question 15

A student records a measurement as 0.00450 g. How many significant figures does this value have?

Accepted Answer

3

Question 16

Which of the following best describes a molecule?

Accepted Answer

A group of two or more atoms joined by strong chemical bonds.

Question 17

Which of the following is a homogeneous mixture?

Accepted Answer

Sports drink

Question 18

Which of the following statements about the nucleus of an atom is correct?

Accepted Answer

It contains most of the atom's mass and is positively charged.

Question 19

If a sample of gold has a mass of 96.5 g and a volume of 5.00 cm$$^3$$, what is its density?

Accepted Answer

$$19.3 \ \mathrm{g/cm^3$}$$

Question 20

Which of the following is an example of a physical property?

Accepted Answer

Boiling point

General Chemistry: Foundations, Matter, Measurement, and Atomic Theory

Guida di studio - Domande di pratica

Study guide - Flashcard