Grade 8_Topic 1-4 Review

Front

What are metalloids?

Back

Metalloids are elements that have properties of both metals and nonmetals. They can conduct electricity and heat better than nonmetals but not as well as metals.

Front

What is the law of conservation of mass?

Back

The law of conservation of mass states that in a chemical reaction, the total mass of the reactants equals the total mass of the products.

Front

How do you determine the density of a substance?

Back

Density is determined by dividing the mass of the substance by its volume (Density = Mass/Volume).

Front

What pH level is considered neutral?

Back

A pH level of 7 is considered neutral, meaning the substance is neither acidic nor basic.

Front

What is the significance of solubility in identifying substances?

Back

Solubility helps identify substances by determining whether they can dissolve in a solvent, which can indicate their chemical properties.

Front

What is the melting point of a substance?

Back

The melting point is the temperature at which a solid becomes a liquid.

Front

What is an acid?

Back

An acid is a substance that donates protons (H+) in a chemical reaction and has a pH less than 7.

Front

What is a base?

Back

A base is a substance that accepts protons (H+) and has a pH greater than 7.

Front

What is the difference between a pure substance and a mixture?

Back

A pure substance has a uniform and definite composition, while a mixture contains two or more substances that retain their individual properties.

Front

What is a chemical reaction?

Back

A chemical reaction is a process where reactants are transformed into products, involving the breaking and forming of chemical bonds.