Unit 6 Test Prep

Front

What is a chemical change?

Back

A chemical change is a process where substances transform into different substances with new chemical properties, often involving a reaction that alters the molecular structure.

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, such as changes in state, shape, or size.

Front

What is the definition of an element?

Back

An element is a pure substance that cannot be broken down into simpler substances by chemical means and is made up of only one type of atom.

Front

What is a heterogeneous mixture?

Back

A heterogeneous mixture is a combination of two or more substances that remain distinct and can be physically separated, such as salad or a mixture of sand and salt.

Front

What is a homogeneous mixture?

Back

A homogeneous mixture is a mixture that has a uniform composition throughout, meaning the individual components are not distinguishable, such as saltwater.

Front

How do you calculate mass from volume and density?

Back

Mass can be calculated using the formula: Mass = Volume × Density. For example, if you have 80 mL of ethanol with a density of 0.7893 g/mL, the mass is 80 mL × 0.7893 g/mL = 63.144 g.

Front

What is the density of a substance?

Back

Density is defined as the mass of a substance per unit volume, typically expressed in grams per milliliter (g/mL) or kilograms per cubic meter (kg/m³).

Front

What is the boiling point of a liquid?

Back

The boiling point is the temperature at which a liquid's vapor pressure equals the external pressure surrounding the liquid, causing it to change into vapor.

Front

What is the melting point of a substance?

Back

The melting point is the temperature at which a solid becomes a liquid at a given pressure, indicating the transition from solid to liquid state.

Front

What is the significance of phase transitions?

Back

Phase transitions, such as melting and boiling, are significant because they represent changes in the state of matter and involve energy changes, affecting physical properties.