Front

What is an element?

Back

An element is a pure substance that cannot be broken down into simpler substances by chemical means. Examples include copper (Cu), nitrogen (N2), and hydrogen (H2).

Front

What is a compound?

Back

A compound is a substance formed when two or more elements are chemically bonded together. For example, sodium chloride (NaCl) is a compound made from sodium (Na) and chlorine (Cl).

Front

What is the average speed formula?

Back

Average speed = Total distance / Total time.

Front

Calculate the average speed of a dog that traveled 12.0 kilometers in 3.0 hours.

Back

Average speed = 12.0 km / 3.0 hr = 4.0 km/hr.

Front

What effect do smaller salt crystals have on the rate of dissolving in water?

Back

Smaller salt crystals increase the surface area, which speeds up the dissolving process.

Front

What is the definition of physical properties?

Back

Physical properties are characteristics of a substance that can be observed or measured without changing the substance's identity, such as color, melting point, and density.

Front

What is the difference between a mixture and a compound?

Back

A mixture is a combination of two or more substances that retain their individual properties, while a compound is a substance formed from two or more elements that are chemically bonded.

Front

What is the significance of surface area in chemical reactions?

Back

Increasing the surface area of a reactant can increase the rate of a chemical reaction by allowing more particles to collide.

Front

What is the average speed of a worm that traveled 25 meters in 5 minutes?

Back

Average speed = 25 m / 5 min = 5 m/min.

Front

What happens to the physical properties of a substance when it forms a compound?

Back

The physical properties of a compound are usually different from those of the individual elements that formed it.