Exploring Chemistry Concepts

What is a chemical reaction? Provide an example.

• A chemical reaction occurs when a solid is heated without any chemical change.

• An example of a chemical reaction is the freezing of water: H2O (liquid) → H2O (solid).

• A chemical reaction is the process of mixing two liquids without any change.

• An example of a chemical reaction is the combustion of methane: CH4 + 2 O2 → CO2 + 2 H2O.

Define acids and bases according to the Arrhenius theory.

• Acids decrease H+ concentration; bases decrease OH- concentration in water.

• Acids increase OH- concentration; bases increase H+ concentration in water.

• Acids and bases do not affect H+ or OH- concentrations in water.

• Acids increase H+ concentration; bases increase OH- concentration in water.

What are the main differences between metals and non-metals?

• Metals are conductive, malleable, and lose electrons; non-metals are insulative, brittle, and gain or share electrons.

• Metals are non-conductive and brittle; non-metals are malleable and gain electrons.

• Metals are insulative and share electrons; non-metals are malleable and lose electrons.

• Metals are brittle and gain electrons; non-metals are conductive and lose electrons.

Explain the trend of electronegativity in the periodic table.

• Electronegativity remains constant across a period and down a group.

• Electronegativity increases across a period and decreases down a group in the periodic table.

• Electronegativity increases down a group and remains constant across a period.

• Electronegativity decreases across a period and increases down a group.

What are carbon compounds and why are they important in chemistry?

• Carbon compounds are primarily used for industrial waste.

• Carbon compounds are not involved in biological processes.

• Carbon compounds are only found in fossil fuels.

• Carbon compounds are essential in chemistry because they form the basis of life and are involved in a wide range of chemical reactions.