Chemistry is the science concerned with the composition, structure, and properties of matter, as well as the changes during chemical reactions. It includes disciplines like general chemistry, inorganic chemistry, organic chemistry, and biochemistry. A substance has a definite composition and set of properties, while an element consists of a single type of atom defined by its atomic number. Compounds contain different elements in specific ratios. Atoms are the basic units that make up elements and can combine through chemical bonds to form compounds.

1. IES Auringis. Jaén. José Cayetano Bautista Expósito 4º ESO. Physics and Chemistry. Unit 7. Chemistry: is the science concerned with the composition, structure, and properties of matter, as well as the changes it undergoes during chemical reactions.

2. Disciplines: General or analytical chemistry: the analysis of material samples to gain an understanding of their chemical composition and structure.

3. Inorganic chemistry: the study of inorganic matter.

4. Organic chemistry: the study of organic (carbon based) matter.

5. Biochemistry: the study of substances found in biological organisms.

6. IES Auringis. Jaén. José Cayetano Bautista Expósito 4º ESO. Physics and Chemistry. Unit 7. Substance is a kind of matter with a definite composition and set of properties.