In the year 1772, Lavoisier performed an experiment on a diamond, in which they put it in a glass jar and focused a large magnifying glass on it under the sun.
They found that the diamond ended up burning away to nothing.
Importantly, Lavoisier noticed the that the weight of the jar didn’t decrease.
Which later helped him realize the law of conservation of mass.
This law states that mass cannot change in a system that is unaffected by matter and energy changes.
Additionally, the burned diamond produced a gas, which we now call carbon dioxide. This also helped Lavoisier understand that diamonds and charcoal are from the same element, which he called carbon.
Another scientific discovery that Lavoisier made were understanding combustion, which is the reaction of certain substances with oxygen at appropriately high temperatures.In fact, Lavoisier is the scientist that discovered and named the elements oxygen, hydrogen, and sulfur.