Chemical Reactions and Conservation of Mass

What is an ion?

• An ion is a charged atom or molecule.
• An ion is a type of chemical bond.
• An ion is a solid crystal structure.
• An ion is a neutral particle.

When are atoms most stable?

• When they have a full outer electron shell.
• When they are exposed to high temperatures.
• When they are in a gaseous state.
• When they have an uneven number of protons.

What happens to electrons in an ionic bond?

• Electrons are transferred from one atom to another.
• Electrons are lost to the surrounding environment.
• Electrons are shared between two atoms.
• Electrons are created during the bond formation.

What happens to electrons in a covalent bond?

• Electrons are transferred to another atom.
• Electrons are shared between atoms.
• Electrons are repelled by the nuclei.
• Electrons are lost to the environment.

What type of bond forms between two nonmetals?

• Covalent Bond

• Ionic bond
• Metallic bond
• Hydrogen bond

What type of bond forms between a metal and a nonmetal?

• Covalent bond
• Metallic bond
• Ionic bond
• Hydrogen bond

Which compounds contains only covalent bonds?

• Ammonia (NH3)
• Carbon dioxide (CO2)
• Water (H2O)
• Sodium chloride (NaCl)

What best describes an endothermic reaction?

• A reaction that absorbs heat from its surroundings.
• A reaction that only happens at high temperatures.
• A reaction that occurs without any heat exchange.
• A reaction that releases heat into the environment.

What is evidence of an exothermic reaction?

• Formation of a solid precipitate in the mixture.
• Release of gas bubbles during the reaction.
• Increase in temperature of the surroundings.
• Decrease in temperature of the surroundings.

What does balancing a chemical equation show?

• It indicates the speed of a chemical reaction.
• It shows the temperature changes during a reaction.
• It reveals the color changes in reactants.
• It demonstrates the conservation of mass in a chemical reaction.