Boron readily reacts with most non-metallic and semi-metallic elements. Some examples and types of reactions include:

1. Reaction with Halogens: Boron reacts with halogens to form covalent halides. For example, when boron reacts with fluorine gas (F2), it forms boron trifluoride (BF3).

2. Reaction with Oxygen: When heated in air or in the presence of oxygen gas, boron forms various oxides. For example, it can react with oxygen to form boron trioxide (B2O3) and various other boron oxides.

3. Reaction with Nitrogen: Boron reacts with nitrogen gas (N2) at high temperatures to form boron nitride (BN). Boron nitride has a layered structure similar to graphite and is a very stable compound.

4. Reaction with Carbon: Boron reacts with carbon to form boron carbides. For example, it reacts with carbon at high temperatures to form boron carbide (B4C), a hard, high-melting-point ceramic material.

5. Reaction with Metals: Boron can react with certain metals to form metal borides. For instance, when boron reacts with aluminum, it forms aluminum boride (AlB2), which is used as a high-temperature material in aerospace and automotive industries.

Boron's reactivity can vary depending on the temperature and conditions of the reaction. It is typically a non-reactive element at room temperature but becomes more reactive at elevated temperatures. The reactions of boron are of importance in various industries and applications, including metallurgy, ceramics, high-temperature materials, semiconductors, and chemical synthesis.