Complete the sentence.
Soaking cucumbers in vinegar to make pickles is a ().
chemical change physical change
Matter is made of very small particles called atoms. Atoms can be linked together by chemical bonds. When two or more atoms link together, they form a molecule.
In a chemical change, the chemical bonds in the molecules break. The atoms then link together to form new molecules. The types of molecules in matter before and after a chemical change are always different.
Burning a piece of paper is a chemical change. As paper burns, paper molecules react with oxygen molecules in the air. This reaction breaks the chemical bonds in the molecules. The atoms then relink and form different molecules. For example, carbon dioxide molecules are created when paper burns.
In a physical change, chemical bonds do not break. The types of molecules in matter before and after a physical change are always the same.
A change of state is a type of physical change. For example, water vaporizing is a physical change. Liquid water and water vapor are made of the same type of matter: water.
Soaking cucumbers in vinegar to make pickles is a chemical change. The vinegar causes the type of matter in the cucumbers to change. The new matter is sour and salty.