9th Chemistry ||What is Diffusion|| and What is Density?

Chemistry is the scientific study of matter, its properties, how and why substances combine or separate to form other substances, and how substances interact with energy. It is often called the central science because it connects physical sciences with life sciences and applied sciences. Chemistry is divided into several branches, including:

1. **Organic Chemistry**: The study of carbon-containing compounds and their reactions.
2. **Inorganic Chemistry**: The study of inorganic compounds, typically those that do not contain carbon-hydrogen bonds.
3. **Physical Chemistry**: The study of how matter behaves on a molecular and atomic level and how chemical reactions occur.
4. **Analytical Chemistry**: The study of the composition of substances and the techniques used to determine the quantities of different components.
5. **Biochemistry**: The study of chemical processes within and related to living organisms.

Chemists use their understanding of these principles to develop new materials, improve existing products, and solve problems in various industries, including pharmaceuticals, environmental science, and manufacturing.
9th Chemistry ||What is Diffusion|| and What is Density?