Chemistry Flashcard

Front

What is a physical change?

Back

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition. Examples include melting, freezing, and dissolving.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new chemical substances. It involves a chemical reaction and includes processes like burning, rusting, and souring.

Front

What happens to sugar when it is crushed and dissolved in water?

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Crushing and dissolving sugar in water is a physical change; the sugar retains its chemical identity and can be recovered by evaporation.

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What is potential energy?

Back

Potential energy is the energy stored in an object due to its position or state. For example, a book on a shelf has potential energy due to its height.

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What is kinetic energy?

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Kinetic energy is the energy of an object in motion. The faster an object moves, the more kinetic energy it has.

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What is the process of tarnishing?

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Tarnishing is a chemical change that occurs when metals react with sulfur or oxygen in the air, leading to a discoloration of the metal surface.

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What are physical properties?

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Physical properties are characteristics of a substance that can be observed or measured without changing its chemical identity, such as color, hardness, and boiling point.

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What is the boiling point?

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The boiling point is the temperature at which a liquid turns into vapor. For water, it is 100°C (212°F) at standard atmospheric pressure.

Front

What is acidity?

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Acidity is a measure of how acidic a solution is, often determined by the concentration of hydrogen ions (H+) present. It is commonly measured using the pH scale.

Front

What is combustibility?

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Combustibility is the ability of a substance to catch fire and burn in the presence of oxygen. Highly combustible materials ignite easily.