Question 1

Which one of the following is an example of a physical property?
A)dynamite explodes
B)meat rots if it is not refrigerated
C)gasoline burns
D)ice floats on top of liquid water
E)a silver platter tarnishes

Accepted Answer

Physical properties are characteristics of matter that can be observed or measured without changing the composition of the substance. In this case, the fact that ice floats on top of liquid water is a physical property because it can be observed without changing the chemical makeup of the water or the ice. The other options involve chemical reactions or changes in composition, making them not examples of physical properties.

Question 2

Complete the following sentence. A scientific law is
A)a tentative explanation for a set of observations that can be tested by further experimentation.
B)a statement describing a relationship between phenomena that is always the same under the same conditions.
C)a unifying principle that explains a body of facts and relations.
D)a model used to visualize the invisible.

Accepted Answer

By definition, a scientific law is a general statement that describes a pattern in nature that is always observed to be true under the same conditions. It is not a tentative explanation, a unifying principle, or a model.

Question 3

Which one of the following represents a physical change? A)water, when heated to 100^$\circ$C, forms steam B)bleach turns hair yellow C)sugar, when heated, becomes brown D)milk turns sour E)apples, when exposed to air, turn brown

Accepted Answer

A physical change involves a change in the physical state or properties of a substance, without changing its chemical identity. Water changing from a liquid to a gas (steam) is a physical change because the substance (water) remains the same chemically, only the physical state has changed. Bleach turning hair yellow, sugar becoming brown, milk turning sour, and apples turning brown all involve chemical changes, where the chemical identity of the substance is altered.

Question 4

A nanometer corresponds to: A)10^{- 2} meters. B)10^{- 3} meters. C)10^{- 6} meters. D)10^{- 9} meters. E)10^{- 12} meters.

Accepted Answer

The answer of A nanometer corresponds to: A)10^{- 2} meters. B)10^{- 3}...

Question 5

A concise verbal or mathematical statement of a relationship between phenomena that is always the same under the same conditions is referred to as
A)a hypothesis.
B)a law.
C)a theory.
D)none of the above.

Accepted Answer

A concise verbal or mathematical statement of a relationship between phenomena that is always the same under the same conditions is referred to as a law.

Question 6

Which one of the following represents a chemical change?
A)boiling water to form steam
B)burning a piece of coal
C)heating lead until it melts
D)mixing iron filings and sand at room temperature
E)breaking glass

Accepted Answer

Burning a piece of coal involves a chemical reaction that produces new substances, including carbon dioxide and ash. The other options involve physical changes, where no new substances are formed.

Question 7

Complete the following sentence. A hypothesis is
A)a tentative explanation for a set of observations that can be tested by further experimentation.
B)a statement describing a relationship between phenomena that is always the same under the same conditions.
C)a unifying principle that explains a body of facts and relations.
D)a model used to visualize the invisible.

Accepted Answer

A hypothesis is a tentative explanation for a set of observations that can be tested by further experimentation. It is a proposed explanation or prediction about a phenomenon or pattern observed in the natural world. Hypotheses serve as the starting point for scientific inquiry and are tested through further observations and experiments to determine their validity.

Question 8

A microliter corresponds to: A)10^{- 2} liters. B)10^{- 3} liters. C)10^{- 6} liters. D)10^{- 9} liters. E)10^{- 12} liters.

Accepted Answer

One microliter (μL) is equal to 10^-6 liters (L).
Using scientific notation, this is expressed as 10^(-6) L.
In the choices given, option C has the correct exponent of -6, which means 10 to the power of -6 multiplied by 1 liter, giving 10^-6 L or 1 μL.

Question 9

A unifying principle that explains a body of facts and relations is referred to as
A)a hypothesis.
B)a law.
C)a theory.
D)none of the above.

Accepted Answer

A hypothesis is a proposed explanation for a phenomenon that needs to be tested. A law is a description of an observed phenomenon that always holds true under certain conditions. A theory is a well-supported explanation for a broad range of observations and experimental results. Therefore, a theory is the best choice for a unifying principle that explains a body of facts and relations.

Question 10

All of the following are properties of tin. Which one is a chemical property of tin? A)Tin can be hammered into a thin sheet. B)At -40^$\circ$C a sheet of tin crumbles to a gray powder. C)Tin melts at 231.9^$\circ$C. D)When a bar of tin is bent, it emits an audible "cry". E)Tin erodes when added to hydrochloric acid, and a clear gas forms.

Accepted Answer

Tin eroding in hydrochloric acid and forming a gas is a chemical reaction, which suggests this is a chemical property of tin. The other options describe physical properties of tin such as its ability to be hammered, its melting point, and how it reacts under certain conditions, but they do not involve chemical reactions.

Question 11

A tentative explanation for a set of observations that can be tested by further experimentation is referred to as
A)a hypothesis.
B)a law.
C)a theory.
D)none of the above.

Accepted Answer

A tentative explanation for a set of observations that can be tested by further experimentation is referred to as a hypothesis.

Question 12

All of the following are properties of sodium. Which one is a physical property of sodium? A)It is a surface turns black when first exposed to air. B)It is a solid at 25^$\circ$C and changes to a liquid when heated to 98^$\circ$C. C)When placed in water it sizzles and a gas is formed. D)When placed in contact with chlorine it forms a compound that melts at 801^$\circ$C. E)Sodium is never found as the pure metal in nature.

Accepted Answer

A physical property is a characteristic of a substance that can be observed or measured without changing its chemical composition. The fact that sodium is a solid at 25C and a liquid at 98C is a physical property. The other choices describe chemical properties, such as its reaction with air, water and chlorine, or its natural occurrence.

Question 13

Which of the following is an example of a physical property? A)corrosiveness of sulfuric acid B)toxicity of cyanide C)flammability of gasoline D)neutralization of stomach acid with an antacid E)lead becomes a liquid when heated to 601^$\circ$C

Accepted Answer

The fact that lead becomes a liquid when heated to a specific temperature is a physical property, as it describes a characteristic of the substance that can be observed or measured without changing its chemical composition. The other answer choices describe chemical properties or reactions.

Question 14

Which of the following does not represent a chemical change? A)a freshly cut apple turns brown B)milk turns sour on standing at room temperature C)when cooled to 0^$\circ$C, liquid water becomes ice D)frying an egg E)fermentation of sugar to alcohol

Accepted Answer

Freezing of liquid water into ice is a physical change, as the molecules in water simply slow down and arrange themselves into a crystalline structure, without any chemical reactions taking place.

Question 15

The SI prefixes milli and mega represent, respectively: A)10⁶ and 10^{- 6}. B)10^{- 3} and 10⁶. C)10³ and 10^{- 6}. D)10^{- 3} and 10⁹. E)10^{- 6} and 10^{- 3}.

Accepted Answer

The prefix milli represents 10^-3 in the SI system, while the prefix mega represents 10^6. So, option B is the only one with the correct prefixes for milli and mega.

Question 16

Choose the response that includes all the items listed below that are pure substances. 
i. orange juice 
ii. steam 
iii. ocean water 
iv. oxygen 
v. vegetable soup
A)i, iii, v
B)ii, iv
C)i, iii, iv
D)iv only
E)all of them are pure

Accepted Answer

Steam (water vapor) and oxygen are both pure substances, consisting of only one type of molecule (H2O for steam and O2 for oxygen), unlike mixtures which contain different substances mixed together.

Question 17

How many milliliters is 0.005 L?
A)0.5 mL
B)5 mL
C)0.50 mL
D)0.000005 mL
E)200 mL

Accepted Answer

To convert L to mL, we multiply by 1000
0.005 L * 1000 = 5 mL

Question 18

The SI prefixes kilo and centi represent, respectively: A)10³ and 10^{- 2}. B)10⁶ and 10^{- 1}. C)10^{- 3} and 10^{- 2}. D)10^{- 6} and 10². E)10² and 10^{- 3}.

Accepted Answer

The answer of The SI prefixes kilo and centi represent,...

Question 19

The SI prefixes nano and deci represent, respectively: A)10^{- 9} and 10^{- 6}. B)10⁶ and 10^{- 3}. C)10³ and 10^{- 3}. D)10⁹ and 10^{- 6}. E)10^{- 9} and 10^{- 1}.

Accepted Answer

The answer of The SI prefixes nano and deci represent,...

Question 20

Complete the following sentence. A theory is
A)a tentative explanation for a set of observations that can be tested by further experimentation.
B)a statement describing a relationship between phenomena that is always the same under the same conditions.
C)a unifying principle that explains a body of facts and relations.
D)a model used to visualize the invisible.

Accepted Answer

The answer of Complete the following sentence. A theory is
A)a...

Quiz 1: Introduction

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

Complete the following sentence. A scientific law is

Which one of the following represents a physical change?

A nanometer corresponds to:

A concise verbal or mathematical statement of a relationship between phenomena that is always the same under the same conditions is referred to as

Which one of the following represents a chemical change?

Complete the following sentence. A hypothesis is

A microliter corresponds to:

A unifying principle that explains a body of facts and relations is referred to as

All of the following are properties of tin. Which one is a chemical property of tin?

A tentative explanation for a set of observations that can be tested by further experimentation is referred to as

All of the following are properties of sodium. Which one is a physical property of sodium?

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

Which of the following does not represent a chemical change?

The SI prefixes milli and mega represent, respectively:

Choose the response that includes all the items listed below that are pure substances. i. orange juice ii. steam iii. ocean water iv. oxygen v. vegetable soup

How many milliliters is 0.005 L?

The SI prefixes kilo and centi represent, respectively:

The SI prefixes nano and deci represent, respectively:

Complete the following sentence. A theory is