Chemical formulas are really important because they link what we learn in chemistry to how things work in the real world. They show us what makes up different compounds and how they are built. This helps scientists share and use chemical knowledge more easily.

How Chemical Formulas Are Used in the Real World:

1. Medicine:

   • In Sweden, more than 1.5 million prescriptions are filled every week.
   • These prescriptions depend on correct chemical formulas for the right amounts and ingredients.
   • For example, the formula for aspirin is $C_9H_8O_4$. This shows its special structure.

2. Agriculture:

   • Chemical fertilizers, like ammonium nitrate ($NH_4NO_3$), are very important for growing crops.
   • They can help increase crop production by up to 20%.

3. Environmental Science:

   • Knowing chemical formulas is helpful for managing pollution.
   • The formula for carbon dioxide is $CO_2$. This is key to figuring out greenhouse gas emissions, which were about 47 million tons in Sweden in 2020.

4. Materials Science:

   • When making materials like polyethylene ($C_{2}H_{4}$), we use chemical formulas to understand how they work and what they can be used for.
   • The global production of polyethylene is over 150 million tons each year.

These examples show that chemical formulas are essential in many different fields and everyday life. They help connect what we learn in theory with how we use that knowledge in practice.