Question

1. which branch of chemistry is concerned with the properties and changes of matter and their relation to energy?

inorganic chemistry
biochemistry
physical chemistry
organic chemistry

Explanation:

• Inorganic chemistry focuses on inorganic compounds (not carbon - based, except some like carbonates). It doesn't mainly deal with the relation between matter's properties/changes and energy.
• Biochemistry is the study of chemical processes within and relating to living organisms. Its focus is on biological systems, not the general properties of matter and energy relation.
• Physical chemistry uses principles of physics to study chemical systems. It is concerned with the properties and changes of matter and how they relate to energy (like thermodynamics, kinetics which involve energy changes in chemical reactions).
• Organic chemistry is the study of carbon - based compounds, mainly focusing on the structure, properties, and reactions of organic molecules, not the general matter - energy relation.

Answer:

C. physical chemistry