Chemistry Quiz: Elements, Compounds, and Reactions

What is the main difference between elements and compounds?

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

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

• Elements are always found in a gaseous state, while compounds are always found in a solid state.

• Elements are always positively charged, while compounds are always negatively charged.

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

• The total mass of the reactants must be less than the total mass of the products in a chemical reaction.

• Mass is destroyed during a chemical reaction.

• Mass is created during a chemical reaction.

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

How are coefficients used in balancing a chemical equation?

• To indicate the electronegativity of the reactants and products.

• To indicate the charge of the reactants and products.

• 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 occurs when two ionic compounds switch cations?

• Combination reaction

• Double-replacement reaction

• Decomposition reaction

• Single-replacement reaction

What type of bond is formed between two nonmetals and involves a sharing of electrons?

• Ionic bond

• Covalent bond

• Polar covalent bond

• Metallic bond

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

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

• 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.

What is the purpose of the oxidation number in determining the chemical formula of a compound?

• To indicate the physical state of the compound.

• To indicate the electronegativity of the compound.

• To indicate the number of isotopes present in the compound.

• To indicate the charge found on the element after it has formed a compound.

What type of reaction occurs when one reactant breaks up into two or more products?

• Combination reaction

• Decomposition reaction

• Single-replacement reaction

• Double-replacement reaction

What did Antoine Lavoisier discover through his experiments with metals and combustion?

• Mass is destroyed during a chemical reaction.

• Mass is created during a chemical reaction.

• The mass of the reactants is always greater than the mass of the products in a nonnuclear reaction.

• The mass of the reactants always equals the mass of the products in a nonnuclear reaction.