Regular EL 4 Chemical Reactions Review

Front

What type of bond usually forms between a metal and a nonmetal?

Back

Ionic bond.

Front

What type of bond usually forms between two nonmetals?

Back

Covalent bond.

Front

What is formed when two atoms share electrons?

Back

Covalent bond.

Front

What type of change occurs when water evaporates from an evaporating dish left under the sun?

Back

Physical change.

Front

How many oxygen atoms are present in the molecule (OH)₂?

Back

2 oxygen atoms.

Front

What is the definition of an ionic bond?

Back

An ionic bond is a type of chemical bond that occurs when electrons are transferred from one atom to another, typically between a metal and a nonmetal.

Front

What is the definition of a covalent bond?

Back

A covalent bond is a type of chemical bond that involves the sharing of electron pairs between atoms, usually between nonmetals.

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.

Front

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

Back

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

Front

What is the significance of the subscript in a chemical formula, such as in (OH)₂?

Back

The subscript indicates the number of atoms of the element in the molecule; in (OH)₂, it indicates there are 2 hydrogen atoms for every 1 oxygen atom.