Dalton made important contributions to our understanding of atoms. Here are the key points:

1. Basic Ideas About Atoms:

   • Dalton suggested that everything is made up of tiny particles called atoms, which cannot be divided into smaller parts.
   • He also said that all atoms of the same element, like oxygen or hydrogen, are exactly the same in weight and properties.

2. Understanding Atomic Mass:

   • He created a way to compare the weights of different atoms. For example, he said that hydrogen has a weight of 1.

3. Law of Multiple Proportions:

   • Dalton showed that when two elements combine, they do so in specific ratios. For example, in carbon dioxide, the weight of carbon compared to oxygen is always in a ratio of 3 to 8 (that means 12 grams of carbon to 32 grams of oxygen).

Dalton's research helped other scientists understand how atoms work and allowed them to create better models in the future.