- Elements are substances that cannot be broken down into simpler substances by chemical means.
- They are made up of one type of atom, which is the smallest unit of matter that can exist.
- Each element has its unique atomic number, which determines the number of protons in the atom's nucleus.
- There are 118 known elements, each with its own unique properties.
Compounds
- Compounds are substances that are made up of two or more elements that are chemically bonded together.
- They have a fixed composition, meaning that the ratio of elements in a compound is always the same.
- When two or more elements react, they form a compound with properties that are different from the original elements.
- There are millions of known compounds, and new ones are being discovered all the time.