1.
Which equation listed below is an example of a synthesis reaction?
Correct Answer
A. A + B yields AB
Explanation
The equation A + B yields AB is an example of a synthesis reaction because it represents the combination of two or more substances to form a single, more complex substance. In this case, A and B react to form the compound AB.
2.
Which equation listed below is an example of a decomposition reaction?
Correct Answer
B. AB yields A + B
Explanation
The equation AB yields A + B is an example of a decomposition reaction because it shows a compound (AB) breaking down into its individual elements (A and B).
3.
Which equation listed below is an example of a single replacement reaction?
Correct Answer
C. AB + C yields AC + B
Explanation
The equation AB + C yields AC + B is an example of a single replacement reaction. In this type of reaction, one element replaces another element in a compound. In this equation, element C replaces element B in the compound AB, forming the new compound AC and releasing element B.
4.
Which equation listed below is an example of a double replacement reaction?
Correct Answer
D. AB + CD yields AC + BD
Explanation
The equation AB + CD yields AC + BD is an example of a double replacement reaction because the reactants (AB and CD) swap partners to form the products (AC and BD). In a double replacement reaction, the positive and negative ions of two compounds switch places to form two new compounds.
5.
The _____________ are on the left side of the yield sign in a chemical reaction and are described as the "ingredients" in a chemical reaction.
Correct Answer
A. Reactants
Explanation
In a chemical reaction, the reactants are the substances that undergo a chemical change to form new substances called products. Reactants are often referred to as the "ingredients" because they are the starting materials that combine or react together to produce the desired chemical reaction. The yield sign in a chemical equation separates the reactants from the products, indicating the direction of the reaction. Therefore, the reactants are located on the left side of the yield sign, while the products are on the right side.
6.
The _____________ are on the right side of the yield sign in a chemical reaction and are described as what is produced in a chemical reaction.
Correct Answer
B. Products
Explanation
In a chemical reaction, the products are the substances that are formed as a result of the reaction. They are located on the right side of the yield sign, indicating that they are what is produced. The reactants, on the other hand, are the substances that undergo the chemical change and are located on the left side of the yield sign. Therefore, the correct answer is "Products."
7.
The arrow in a chemical reaction means all of the following except
Correct Answer
D. Attaches to
Explanation
The arrow in a chemical reaction represents the direction of the reaction, indicating the conversion of reactants into products. It does not signify the attachment of any specific element or compound to another. Therefore, the arrow does not mean "attaches to" in a chemical reaction.
8.
The Law of Conservation of Matter states
Correct Answer
A. Matter cannot be created or destroyed in a chemical reaction
Explanation
The Law of Conservation of Matter states that matter cannot be created or destroyed in a chemical reaction. This means that the total mass of the reactants must be equal to the total mass of the products. While matter can undergo physical or chemical changes, it is never truly created or destroyed in a chemical reaction.
9.
Painting a pencil red is a chemical change.
Correct Answer
B. False
Explanation
Painting a pencil red is not a chemical change, but rather a physical change. This is because the composition and properties of the pencil itself do not change. The pencil is simply being coated with a layer of red paint, which can be easily removed without altering the chemical structure of the pencil.
10.
Check ALL of the properties listed below that are chemical properties.
Correct Answer(s)
A. Flammability
B. Combustability
D. Affected by light
E. Ability to rust
Explanation
The properties listed that are chemical properties include flammability, combustibility, affected by light, and ability to rust. These properties describe the behavior of a substance during a chemical reaction or interaction with other substances. Flammability and combustibility refer to the ability of a substance to burn or support combustion. Being affected by light suggests that the substance undergoes a chemical change when exposed to light. Ability to rust indicates that the substance can undergo a chemical reaction with oxygen, leading to the formation of rust.
11.
Select ALL the answers listed below that are examples of a physical change.
Correct Answer(s)
A. Color change
D. Water changing to steam
E. Wood being shreded
Explanation
The given answers "color change," "water changing to steam," and "wood being shredded" are examples of physical changes. A physical change refers to a change in the physical properties of a substance without altering its chemical composition. In the case of a color change, the substance's appearance is altered, but its chemical composition remains the same. Similarly, when water changes to steam, it undergoes a physical change from a liquid to a gas. Lastly, wood being shredded is a physical change as it involves breaking down the physical structure of the wood without altering its chemical composition.
12.
Select ALL the choices below that are examples of a chemical change.
Correct Answer(s)
A. Iron rusting
B. Color change as an indicator
C. Baking soda fizzing/bubbling when mixed with vinegar
Explanation
Iron rusting is a chemical change because it involves the oxidation of iron in the presence of oxygen, forming iron oxide. Color change as an indicator is also a chemical change because it involves a chemical reaction that causes a change in color. Baking soda fizzing/bubbling when mixed with vinegar is a chemical change because it involves a chemical reaction between the two substances, producing carbon dioxide gas. Water turning into ice is a physical change because it is a phase change from liquid to solid. Breaking a pencil is a physical change because it involves the breaking of the pencil, but no new substances are formed.
13.
Select ALL the choices below that are examples of a physical property.
Correct Answer(s)
A. Bitter taste
B. Odor
D. Melting point
Explanation
The given choices that are examples of physical properties are bitter taste, odor, and melting point. A physical property is a characteristic of a substance that can be observed or measured without changing the substance's identity. Bitter taste and odor are sensory characteristics that can be perceived without altering the substance. Melting point is the temperature at which a substance changes from a solid to a liquid state, which is also a measurable physical property.
14.
Which of the following best describes something that has mass and takes up space?
Correct Answer
B. Matter
Explanation
Matter is the correct answer because it refers to anything that has mass and occupies space. In the context of physics and chemistry, matter is the substance that makes up all physical objects and can exist in various states such as solid, liquid, or gas. This term encompasses everything from atoms and molecules to larger entities like planets and stars. Therefore, matter is the most appropriate choice to describe something that has mass and takes up space.
15.
The study of matter and how it changes is best described as
Correct Answer
A. Chemistry
Explanation
The study of matter and how it changes refers to the field of chemistry. Chemistry is the scientific discipline that investigates the composition, properties, and behavior of matter, as well as the changes it undergoes during chemical reactions. It involves the study of atoms, molecules, elements, compounds, and their interactions. By examining the structure and properties of substances, chemists can gain insights into the fundamental nature of matter and develop new materials and processes for various applications.
16.
A change in matter that results in something new is called
Correct Answer
C. Chemical change
Explanation
A change in matter that results in something new is called a chemical change. This type of change occurs when the chemical composition of a substance is altered, resulting in the formation of new substances with different properties. Examples of chemical changes include burning, rusting, and digestion.
17.
A characteristic that can be observed without changing the substance is called a ______________.
Correct Answer
A. pHysical property
Explanation
A physical property is a characteristic that can be observed without changing the substance. This means that even if we manipulate or interact with the substance, its physical properties will remain the same. Examples of physical properties include color, density, melting point, boiling point, and conductivity.
18.
A(n) _____________ chemical reaction occurs when heat is absorbed into a chemical reaction.
Correct Answer
C. Endothermic
Explanation
An endothermic chemical reaction occurs when heat is absorbed into the reaction. This means that the reactants absorb energy from their surroundings, usually in the form of heat, causing the reaction to feel cold to the touch. The energy absorbed is used to break the bonds between the atoms in the reactants, allowing new bonds to form and resulting in the products of the reaction.
19.
A(n) _____________ chemical reaction occurs when heat is released from a chemical reaction.
Correct Answer
D. Exothermic
Explanation
An exothermic chemical reaction occurs when heat is released from the reaction. This means that the reactants have more energy than the products, and the excess energy is given off in the form of heat. This can often be observed by a rise in temperature in the surroundings.
20.
Select ALL the options listed below that are a sign of a chemical reaction.
Correct Answer(s)
A. Temperature increase
B. Temperature decrease
C. Light is produced
F. Fizzing/bubbling
Explanation
When a chemical reaction occurs, it often results in a temperature increase or decrease. This is because energy is either released or absorbed during the reaction. Light is also produced in some chemical reactions, such as in combustion reactions or when certain compounds are excited. Fizzing or bubbling is a sign of a chemical reaction as it indicates the release of gas. However, change in shape and food coloring in water are not necessarily signs of a chemical reaction as they can occur due to physical changes or mixing of substances.
21.
A characteristic of a substance that describes its ability to change into something new is called a(n)
Correct Answer
B. Chemical property
Explanation
A chemical property is a characteristic of a substance that describes its ability to change into something new. Unlike physical properties, which describe the appearance or state of a substance, chemical properties involve the substance's composition and its reactions with other substances. Chemical properties can include things like flammability, reactivity, and toxicity. These properties determine how a substance will interact with other substances and can help identify and classify different substances.