A chemical is a substance with a specific composition and properties that result from the arrangement of its atoms. Chemicals can be found in various forms, including solids, liquids, and gases. They can undergo chemical reactions to form new substances. Chemicals are essential for life and are used in numerous applications, including medicine, agriculture, and industry.
Key Concepts to Understand:
Atoms and Elements:Atoms are the basic building blocks of matter. Elements are made up of a single type of atom, and each element has its own unique chemical properties.
Chemical Reactions:Chemical reactions occur when substances interact to form new compounds. This process involves the breaking and forming of chemical bonds.
Chemical Bonds: Chemical bonds are the forces that hold atoms together in a compound. Common types of chemical bonds include ionic bonds and covalent bonds.
Types of Chemicals: Chemicals can be classified into elements, compounds, and mixtures. Elements are pure substances made up of only one type of atom, while compounds are made up of two or more different elements combined in fixed proportions. Mixtures are combinations of two or more substances that are not chemically bonded.
Chemical Properties and Changes: Chemical properties describe how a substance behaves in a chemical reaction. Chemical changes involve the formation of new substances with different properties.
Study Guide:
Use the following study guide to review and reinforce your understanding of the topic "chemical":
Define the terms "atom" and "element." Give examples of different elements.
Explain the difference between a chemical reaction and a physical change. Provide examples of each.
Describe the types of chemical bonds and their characteristics.
Differentiate between elements, compounds, and mixtures. Provide examples of each.
Identify the chemical properties of common substances found in everyday life.
From Molecules to Organisms: Structures and Processes
Students who demonstrate understanding can:
Construct a scientific explanation based on evidence for the role of photosynthesis in the cycling of matter and flow of energy into and out of organisms.