1: An atom is nuclear energy that is extremely small. It is the smallest unit of matter that forms a chemical element. It is the building block for all matter in the universe. They are made up of even smaller particles. Particles that make up an atom are electrons, neutrons, and protons.
2. What’s different inside of an atom to make them into different elements is that the number of protons in an atom is the defining feature of an atom. This is what makes a element different from another.
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