Nitrogen and hydrogen don't "form" in the sense that they are created. They are fundamental elements, meaning they are the building blocks of matter and cannot be broken down into simpler substances.

Here's how they exist in nature:

* Nitrogen (N): It's the most abundant gas in Earth's atmosphere, making up about 78% of the air we breathe. It exists as a diatomic molecule (N₂), meaning two nitrogen atoms are bonded together.

* Hydrogen (H): Hydrogen is the most abundant element in the universe. It exists in the universe primarily as atomic hydrogen (H), which is a single proton with a single electron. On Earth, it's found primarily as a component of water (H₂O) and other compounds, but it also exists as diatomic hydrogen gas (H₂).

How Nitrogen and Hydrogen Combine:

Nitrogen and hydrogen don't spontaneously combine under normal conditions. However, they can be forced to react under specific conditions to form ammonia (NH₃). This process is called the Haber-Bosch process:

1. High Temperature: The reaction requires very high temperatures (around 400-500°C).

2. High Pressure: It also needs high pressures (around 200 atmospheres).

3. Catalyst: A catalyst (typically iron) is used to speed up the reaction.

The Haber-Bosch process is incredibly important because ammonia is a crucial ingredient in fertilizers and other industrial chemicals. It's one of the most significant inventions of the 20th century, allowing us to produce food for a rapidly growing population.