1.
If you describe a sugar's color and taste, you are identifying its chemical properties.
Correct Answer
B. False
Explanation
Describing a sugar's color and taste does not involve identifying its chemical properties. Color and taste are physical properties of sugar, not chemical properties.
2.
Organic compounds are those that contain calcium.
Correct Answer
B. False
Explanation
This statement is false. Organic compounds do not contain calcium. Organic compounds are compounds that contain carbon atoms bonded to hydrogen atoms, along with other elements such as oxygen, nitrogen, sulfur, and phosphorus. Calcium is not typically found in organic compounds.
3.
The atoms of one element are different than the atoms of another element.
Correct Answer
A. True
Explanation
The statement is true because each element is defined by the number of protons in its atoms. Different elements have different numbers of protons, which means their atoms are different. This distinction in atomic structure is what gives elements their unique properties and allows them to combine and form compounds. Therefore, the atoms of one element are indeed different from the atoms of another element.
4.
An atom is smaller than a molecule.
Correct Answer
A. True
Explanation
An atom is indeed smaller than a molecule because an atom is the basic unit of matter, consisting of a nucleus (containing protons and neutrons) surrounded by electrons. A molecule, on the other hand, is formed when two or more atoms chemically bond together. Since a molecule is composed of multiple atoms, it is typically larger in size compared to an individual atom. Therefore, the statement "An atom is smaller than a molecule" is true.
5.
A solution may be either a heterogeneous or homogeneous mixture
Correct Answer
B. False
Explanation
A solution can only be a homogeneous mixture, not a heterogeneous mixture. A homogeneous mixture is a uniform mixture where the components are evenly distributed throughout, while a heterogeneous mixture is a non-uniform mixture where the components are not evenly distributed. Therefore, the statement that a solution may be either a heterogeneous or homogeneous mixture is false.
6.
If a material is a pure substance, you can expect it to react the same way under a given set of circumstances.
Correct Answer
A. True
Explanation
If a material is a pure substance, it means that it is composed of only one type of element or compound. Since pure substances have a consistent and definite composition, they will react in the same way under a given set of circumstances. This is because the chemical properties of a substance are determined by its composition, and if the composition is consistent, the reactions will be consistent as well. Therefore, it is reasonable to expect a pure substance to react the same way under a given set of circumstances.
7.
Two different samples of a heterogeneous mixture always have the same qualities.
Correct Answer
B. False
Explanation
Two different samples of a heterogeneous mixture do not always have the same qualities. A heterogeneous mixture is a combination of different substances that are not evenly distributed. The composition and properties of each sample can vary depending on the distribution of the components. Therefore, it is not true that two different samples of a heterogeneous mixture always have the same qualities.
8.
Elements can join physically to form compounds.
Correct Answer
B. False
Explanation
This statement is false because elements do not join physically to form compounds. Compounds are formed when elements chemically combine through bonding, either by sharing electrons (covalent bonding) or transferring electrons (ionic bonding). Physical joining refers to a mixture, where elements are simply mixed together without any chemical bonding.
9.
Gas, liquid, and solid are the three basic phases in which matter is found.
Correct Answer
A. True
Explanation
Gas, liquid, and solid are indeed the three basic phases in which matter is found. These phases are determined by the arrangement and movement of particles. In the gas phase, particles are far apart and move freely. In the liquid phase, particles are closer together and can move past each other. In the solid phase, particles are tightly packed and vibrate in place. This classification of matter into these three phases is fundamental in understanding the behavior and properties of different substances.
10.
A substance's properties give it its idenity.
Correct Answer
A. True
Explanation
The statement is true because a substance's properties, such as its physical and chemical characteristics, determine its identity. These properties can include things like color, odor, density, melting point, and reactivity. By examining and analyzing these properties, scientists can identify and classify different substances. Therefore, the properties of a substance play a crucial role in defining its identity.
11.
A substance shows its chemical properties in how it reacts with other substances.
Correct Answer
A. True
Explanation
Chemical properties of a substance refer to its ability to undergo chemical reactions and form new substances. These properties are determined by the arrangement and behavior of the atoms and molecules in the substance. When a substance reacts with other substances, it can exhibit various chemical properties such as reactivity, acidity, basicity, or combustibility. Therefore, the statement "A substance shows its chemical properties in how it reacts with other substances" is true because the reactions of a substance with other substances provide insights into its chemical behavior and properties.
12.
Matter includes people, places, and ideas.
Correct Answer
B. False
Explanation
The statement "Matter includes people, places, and ideas" is incorrect. Matter refers to anything that has mass and occupies space, such as solid, liquid, or gas. People, places, and ideas are not physical substances and do not fall under the category of matter. Therefore, the correct answer is false.
13.
Substances lose their original properties when combined in a mixture.
Correct Answer
B. False
Explanation
When substances are combined in a mixture, they do not lose their original properties. In a mixture, the substances retain their individual characteristics and can be separated through physical means. This is different from a chemical reaction, where substances react and form new compounds with different properties. Therefore, the given statement is false.
14.
The molecules in a single compound are identical.
Correct Answer
A. True
Explanation
In a single compound, all the molecules are made up of the same type and number of atoms. This means that the arrangement of atoms in each molecule is identical, resulting in identical properties and characteristics. Therefore, the statement that "the molecules in a single compound are identical" is true.
15.
A substance's phase is one of its chemical properties.
Correct Answer
B. False
Explanation
The statement is false because a substance's phase is not considered one of its chemical properties. Phase refers to the physical state of a substance (solid, liquid, gas) and can change without altering the substance's chemical composition. Chemical properties, on the other hand, describe how a substance interacts with other substances and undergoes chemical reactions.
16.
Which of the following is an example of a compound?
Correct Answer
B. Carbon dioxide
Explanation
A compound is a substance formed when two or more elements are chemically combined in a fixed ratio. Carbon dioxide (CO2) is a compound because it consists of one carbon atom and two oxygen atoms chemically bonded together. Saltwater is a mixture of salt and water, air is a mixture of gases, and sand is a mixture of different minerals.