Chemistry Quiz: Elements, Compounds, and Reactions

What is the main difference between elements and compounds?

• Elements are always reactive, while compounds are stable and non-reactive.

• Elements are always in a gaseous state, while compounds can be in solid, liquid, or gaseous states.

• Elements are always found in nature, while compounds are only created in a laboratory setting.

• Elements are made of only one type of atom, while compounds are made of two or more different types of atoms.

What is the law of conservation of mass in a chemical reaction?

• The total mass of the reactants equals the total mass of the products in a chemical reaction.

• Mass is created during a chemical reaction.

• Mass is destroyed during a chemical reaction.

• The total mass of the reactants is always less than the total mass of the products in a chemical reaction.

How are coefficients used in a balanced chemical equation?

• To indicate the color change that occurs during the reaction.

• To indicate the temperature at which the reaction occurs.

• To indicate the physical state of the reactants and products.

• To indicate the number of atoms, molecules, or formula units in a reaction.

What type of reaction is represented by the equation: A + X → AX?

• Single-replacement reaction

• Decomposition reaction

• Combination reaction

• Double-replacement reaction

In a single-replacement reaction, what happens to the element (B) in the compound (BX)?

• It breaks up into two or more products.

• It combines with another element to form a new compound.

• It remains unchanged in the products.

• It becomes a single element in the products.

What type of reaction occurs when a compound reacts with oxygen, producing carbon dioxide and water vapor?

• Decomposition reaction

• Combination reaction

• Combustion reaction

• Single-replacement reaction

What is the main difference between ionic and covalent bonds?

• Covalent bonds are always formed in a gaseous state, while ionic bonds can be in solid, liquid, or gaseous states.

• Ionic bonds are stronger than covalent bonds.

• Ionic bonds involve a transfer of electrons, while covalent bonds involve a sharing of electrons.

• Ionic bonds only occur between metals, while covalent bonds only occur between nonmetals.

What is the purpose of the periodic table in determining chemical formulas?

• To predict the color change that occurs during a reaction.

• To identify the number of valence electrons and oxidation numbers of the elements.

• To determine the physical state of the elements.

• To indicate the temperature at which the reaction occurs.

What is the general trend for elements in Group 1A of the periodic table?

• They have one valence electron that is easily transferred, forming a cation with a 1+ charge.

• They have two valence electrons that can be readily transferred, forming a cation with a 2+ charge.

• They have five valence electrons, which leads to these atoms gaining three electrons from other elements, creating an anion with a 3- charge.

• They have eight valence electrons in their outer shell, except for helium, which only has two.

What is the purpose of using the coefficients in a chemical equation?

• To ensure the number of atoms in the reactants equals the number of atoms in the products.

• To indicate the physical state of the reactants and products.

• To indicate the color change that occurs during the reaction.

• To indicate the temperature at which the reaction occurs.