1.
Which of the following is not a mixture?
Correct Answer
D. Compound
Explanation
A compound is not a mixture because it is a substance made up of two or more elements chemically combined in a fixed ratio. In a compound, the elements lose their individual properties and form a new substance with its own unique properties. In contrast, a mixture is a combination of two or more substances that are physically combined and can be separated by physical means. Both homogeneous and heterogeneous mixtures are examples of mixtures, where the components are not chemically bonded and retain their individual properties.
2.
What is the study of the properties of matter?
Correct Answer
B. Chemistry
Explanation
Chemistry is the study of the properties of matter, including its composition, structure, properties, and the changes it undergoes during chemical reactions. It involves the study of atoms, molecules, and compounds, and how they interact with each other. Chemistry helps us understand the behavior of different substances, their reactions, and their applications in various fields such as medicine, industry, and environmental science. It is a fundamental science that provides a foundation for other disciplines such as biology and physics.
3.
What is a combination of two or more atoms?
Correct Answer
A. Molecule
Explanation
A molecule is a combination of two or more atoms that are chemically bonded together. It is the smallest unit of a compound that retains the chemical properties of that compound. Molecules can be made up of atoms of the same element or different elements. They are held together by chemical bonds, which can be covalent or ionic. Therefore, a molecule is the correct answer for the given question as it accurately describes the combination of atoms.
4.
What shows the elements in compounds and the ratio of atoms?
Correct Answer
C. Chemical formula
Explanation
A chemical formula is a notation that represents the elements present in a compound and the ratio of atoms in that compound. It provides information about the types and numbers of atoms that are combined to form the compound. This allows scientists to understand the composition of a compound and predict its properties and behavior. Therefore, a chemical formula is the correct answer as it accurately describes the elements in compounds and their atomic ratios.
5.
What is the matter?
Correct Answer
C. All of the above
Explanation
The correct answer is "All of the above" because matter refers to anything that has mass and takes up space. This includes both solid substances and any other form of matter, such as liquids or gases. Therefore, all the options provided in the question are correct explanations for what matter is.
6.
What can't be observed without changing it into another substance?
Correct Answer
D. Chemical property
Explanation
Chemical property refers to the characteristics of a substance that can only be observed or measured when the substance undergoes a chemical change or reaction. Unlike physical properties, such as color or density, which can be observed without altering the substance, chemical properties can only be determined through chemical reactions. Therefore, chemical property cannot be observed without changing the substance into another substance.
7.
You can see the different parts in any homogeneous mixture.
Correct Answer
B. False
Explanation
In a homogeneous mixture, the different parts are not visible because they are evenly distributed throughout the mixture. This means that the mixture has a uniform composition and appears as a single phase. Therefore, the statement that "you can see the different parts in any homogeneous mixture" is incorrect.
8.
What is a chemical formula?
Correct Answer
C. All of the above
Explanation
A chemical formula is a representation of a compound that shows the ratio of atoms present in it. It also shows the elements that are present in the compound. Therefore, the correct answer is "All of the above." The statement "the makeup of an atom" is not entirely accurate as a chemical formula represents the composition of a compound, not an individual atom.
9.
How can you separate a mixture?
Correct Answer
D. All of the above
Explanation
All of the above methods can be used to separate a mixture. Magnetic attraction is used to separate a mixture containing magnetic substances by attracting them with a magnet. Filtration is used to separate a mixture of solid and liquid components by passing it through a filter, which allows the liquid to pass through while retaining the solid particles. Distillation is used to separate a mixture of liquids with different boiling points by heating the mixture and collecting the vapor that condenses at different temperatures. Therefore, all three methods mentioned can be used to separate different types of mixtures.
10.
H2O, NaCl, HCl (the written expressions) are all examples of what?
Correct Answer
B. Chemical formulas
Explanation
The given written expressions, H2O, NaCl, and HCl, are all examples of chemical formulas. Chemical formulas are a way to represent the composition of a chemical compound using symbols and subscripts to indicate the types and numbers of atoms present. In this case, H2O represents water, NaCl represents table salt, and HCl represents hydrochloric acid. Therefore, the correct answer is chemical formulas.
11.
Which of these is not a physical property?
Correct Answer
B. Flammability
Explanation
Flammability is not a physical property because it refers to the ability of a substance to burn or ignite. Physical properties, on the other hand, are characteristics that can be observed or measured without changing the chemical composition of a substance. Melting point, density, and conductivity are physical properties as they describe the behavior or characteristics of a substance without involving any chemical reactions.