Exploring Atoms and Molecules
10th Grade · Science · 45 min
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Learning Objective
I can describe the basic structure of atoms and how they combine to form molecules.
- 1
Democritus first proposed the idea of the atom, calling them Atomos, meaning uncuttable, though he lacked evidence to support his claim.
- 2
Lavoisier found that certain pure substances, called elements, could not be broken down further through chemical reactions, leading to the discovery of the 118 elements on the periodic table.
- 3
John Dalton discovered that elements react in small, whole number ratios, suggesting that elements are made of tiny, indivisible units called atoms, which are nearly identical in size within a single element.