7th Grade Science Comprehensive Test

Front

What is the Bohr Model of the atom?

Back

The Bohr Model is a representation of the atom that shows electrons existing at specific energy levels, resembling a planetary system.

Front

What is condensation in the water cycle?

Back

Condensation is the process where water vapor cools and forms droplets of liquid water.

Front

How many elements are in the chemical formula H2SO4?

Back

There are 3 elements in the chemical formula H2SO4: Hydrogen (H), Sulfur (S), and Oxygen (O).

Front

What type of reaction is represented by H2 + O2 → H2O?

Back

This is a synthesis reaction, where two or more reactants combine to form a single product.

Front

What does Dalton's model of the atom represent?

Back

Dalton's model represents the atom as a solid, indivisible sphere, which was one of the first scientific theories of atomic structure.

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.

Front

What is the definition of a chemical reaction?

Back

A chemical reaction is a process that leads to the transformation of one set of chemical substances into another.

Front

What is evaporation?

Back

Evaporation is the process by which liquid water turns into water vapor, usually due to heat.

Front

What is the difference between a physical change and a chemical change?

Back

A physical change alters the form of a substance but not its chemical composition, while a chemical change results in the formation of new substances.

Front

What is the law of conservation of mass?

Back

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction.