1.
Which of the following is an example of a pure substance?
Correct Answer
C. Gold
Explanation
A pure substance consists of only one type of element or compound with uniform and definite composition. Gold is an example of a pure substance because it is made up of only one type of atom (Au), making it a pure element. In contrast, air is a mixture of gases (nitrogen, oxygen, etc.), saltwater is a mixture of water and salt, and sand is composed of multiple materials like silica, meaning these are all mixtures rather than pure substances.
2.
What are the two types of Mixtures
Correct Answer
D. Homogenous and Heterogeneous
Explanation
The correct answer is Homogenous and Heterogeneous. Homogeneous mixtures have a uniform composition throughout, meaning that the components are evenly distributed and not easily distinguishable. Heterogeneous mixtures, on the other hand, have an uneven composition, with the components being visibly separate and easily distinguishable.
3.
One specific type of homogeneous mixture is
Correct Answer
C. A solution
Explanation
A solution is a specific type of homogeneous mixture where one or more substances are dissolved in a solvent. It is composed of solutes, which are the substances being dissolved, and a solvent, which is the substance that dissolves the solutes. The solutes and solvent are evenly distributed throughout the solution, resulting in a uniform composition. This distinguishes a solution from other types of mixtures, such as compounds or elements, which have different properties and characteristics.
4.
Cookies and cream ice cream would be classified as
Correct Answer
B. A heterogenous mixture
Explanation
Cookies and cream ice cream would be classified as a heterogeneous mixture because it consists of different components that are visibly distinguishable. In this case, the ice cream contains visible cookie pieces mixed with a cream base. The different components do not blend uniformly throughout the mixture, making it heterogeneous.
5.
Table salt, also known as sodium chloride would be classified as
Correct Answer
D. A compound
Explanation
Table salt, also known as sodium chloride, would be classified as a compound. This is because it is made up of two elements, sodium and chlorine, that are chemically bonded together in a fixed ratio. In a compound, the elements lose their individual properties and form a new substance with unique properties. In the case of sodium chloride, it has a crystalline structure, a high melting point, and is soluble in water. Therefore, it meets the criteria for being classified as a compound.
6.
A glass of Kool Aid would be classified as
Correct Answer
A. A homogeneous mixture
Explanation
A glass of Kool Aid would be classified as a homogeneous mixture because it is a combination of water, sugar, and flavoring that is evenly distributed throughout the solution. The individual components of the mixture cannot be easily separated or distinguished, indicating that it is a homogeneous mixture.
7.
Helium would be classified as
Correct Answer
C. An element
Explanation
Helium would be classified as an element because it is a pure substance that cannot be broken down into simpler substances by chemical means. Elements consist of only one type of atom, and helium is made up of only helium atoms. It is not a mixture because it does not contain different substances that are physically combined. Additionally, it is not a compound because it does not consist of different elements chemically bonded together. Therefore, helium is correctly classified as an element.
8.
The prefix homo- means
Correct Answer
A. Same
Explanation
The prefix "homo-" is derived from the Greek word "homos," which means "same." Therefore, when "homo-" is used as a prefix in English, it indicates similarity or sameness.
9.
Two elements chemically combined defines
Correct Answer
D. A compound
Explanation
When two elements chemically combine, they form a compound. A compound is a substance composed of two or more different elements that are chemically bonded together in a fixed ratio. In a compound, the elements lose their individual properties and form a new substance with unique properties. This is different from a homogeneous or heterogeneous mixture, where the elements or compounds are physically mixed together but not chemically bonded. Therefore, the correct answer is a compound.
10.
Two substances physically combined and that appears the same throughout is classified as
Correct Answer
A. A homogeneous mixture
Explanation
A homogeneous mixture is a combination of two or more substances that are uniformly distributed and appear the same throughout. In other words, the components of a homogeneous mixture are evenly mixed at the molecular level, resulting in a uniform composition. This is different from a heterogeneous mixture, where the components are not evenly distributed and may be easily distinguished. An element is a pure substance made up of only one type of atom, while a compound is a substance composed of two or more different elements chemically bonded together.