Question 1

Which of the following best describes a chemical transformation?

Accepted Answer

A process in which the identity of participating chemical particles changes.

Question 2

Which of the following is an example of a pure substance?

Accepted Answer

Table salt ($$\mathrm{NaCl})$$

Question 3

Which statement correctly distinguishes between a compound and an element?

Accepted Answer

An element is composed of atoms of only one kind, while a compound contains atoms of more than one kind.

Question 4

Which of the following is a chemical property of water?

Accepted Answer

Ability to produce hydrogen and oxygen upon passing electric current

Question 5

Which of the following is a physical change?

Accepted Answer

Boiling of water

Question 6

Which of the following elements is the most abundant in the universe?

Accepted Answer

Hydrogen

Question 7

Which of the following is a homogeneous mixture?

Accepted Answer

Clean air

Question 8

Which instrument allows scientists to observe individual atoms on a surface?

Accepted Answer

Scanning tunneling microscope

Question 9

Which of the following is NOT a monoatomic element under standard conditions?

Accepted Answer

Oxygen ($$\mathrm{O}_2)$$

Question 10

Which of the following is an example of a chemical change?

Accepted Answer

Burning of gasoline in a car engine

Question 11

Which of the following statements about mixtures is correct?

Accepted Answer

Mixtures have a variable composition and can be separated by physical methods.

Question 12

Which of the following is an allotrope of carbon?

Accepted Answer

Diamond

Question 13

Which of the following is a correct example of a compound?

Accepted Answer

Water ($$\mathrm{H}_2\mathrm{O})$$

Question 14

Which of the following is a heterogeneous mixture?

Accepted Answer

Dusty air

Question 15

Which of the following is NOT a physical property?

Accepted Answer

Ability to react with acid

Question 16

Which of the following statements about elements and compounds is correct?

Accepted Answer

Compounds are composed of atoms of two or more elements chemically bonded together.

Question 17

Which of the following is a correct example of a physical change?

Accepted Answer

Boiling of liquid nitrogen

Question 18

Which of the following is a correct statement about the periodic table?

Accepted Answer

Some elements on the periodic table are produced artificially.

Question 19

Which of the following is a correct example of a mixture?

Accepted Answer

Sea water

Question 20

Which of the following is a correct statement about physical and chemical changes?

Accepted Answer

Chemical changes alter the identity of chemical species involved.

CHEM 135 General Chemistry for Engineers: Syllabus and Introduction to Matter

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