Question 1

Which of the following statements best describes a chemical change?

Accepted Answer

A substance reacts with oxygen to form a new compound.

Question 2

Which of the following is the correct way to express 0.00056 in scientific notation?

Accepted Answer

$$5.6 	imes 10$$^{-5}$$

Question 3

A patient’s temperature is measured as 102.5 $$^{\circ}F. $$What is this temperature in Celsius?

Accepted Answer

$$39.2^{\circ}C$$

Question 4

Which of the following is NOT a physical property?

Accepted Answer

Ability to react with acid

Question 5

How many significant figures are in the measurement 0.00450 g?

Accepted Answer

3

Question 6

Which of the following best describes an isotope?

Accepted Answer

Atoms of the same element with different numbers of neutrons

Question 7

A neutral atom of chlorine has an atomic number of 17 and a mass number of 35. How many neutrons does it have?

Accepted Answer

18

Question 8

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

Accepted Answer

Magnesium (Mg)

Question 9

Which of the following is the correct electron configuration for a neutral oxygen atom?

Accepted Answer

$$1s^2$$\ $$2s^2$$\ $$2p^4$$

Question 10

Which of the following statements about the periodic table is TRUE?

Accepted Answer

Elements in the same group have similar chemical properties.

Question 11

Which of the following best describes the difference between ionic and covalent bonds?

Accepted Answer

Ionic bonds involve the transfer of electrons; covalent bonds involve the sharing of electrons.

Question 12

Which of the following compounds is ionic?

Accepted Answer

NaCl

Question 13

A sample contains 3.0 moles of carbon atoms. What is the mass of the sample in grams? (Atomic mass of C = 12.0 g/mol)

Accepted Answer

$$36.0 g$$

Question 14

Which of the following is the correct Lewis structure for a water molecule (H$$_2O$$)?

Accepted Answer

O atom with two single bonds to H atoms and two lone pairs on O

Question 15

Which of the following is a correct statement about valence electrons?

Accepted Answer

Valence electrons are responsible for chemical bonding.

Question 16

Which of the following ions has the same electron configuration as neon?

Accepted Answer

Na$$^+$$

Question 17

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

Accepted Answer

Ca$$_3(PO$_4$$)$$_2$$

Question 18

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

Accepted Answer

They have a full complement of valence electrons.

Question 19

Which of the following is the correct order of increasing electronegativity?

Accepted Answer

Na \u003c Cl \u003c F

Question 20

A compound contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. What is its empirical formula?

Accepted Answer

CH$$_2O$$

GOB Chemistry Study Guide: Matter, Measurements, Atoms, and Compounds

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