Measurement of Matter

Flashcards covering basic concepts of chemical combination, Dalton's atomic theory, and atomic measurements.

Molecules

Formed by joining atoms of different elements to each other when forming a compound.

Dalton's Atomic Theory

A theory based on the laws of chemical combination, on which molecular formulas are based.

Laws of chemical combination

Laws discovered by scientists through experiments during the 18th and 19th centuries regarding how the composition of substances changes during a chemical reaction.

Law of conservation of matter

Proposed by Antoine Lavoisier in 1785; it states that mass remains constant during a chemical reaction, the total mass of reactants equals the total mass of products, and matter is neither created nor destroyed.

Antoine Lavoisier

The scientist who proposed the Law of conservation of matter in 1785.

Law of constant proportion

Proposed by J. L. Proust in 1794; it states that elements in a compound are always present in a fixed ratio by mass.

J. L. Proust

The scientist who proposed the Law of constant proportion in 1794.

Mass ratio in water ($H_2O$)

The ratio of Hydrogen (H) to Oxygen (O) is $1:8$.

Mass ratio in Carbon dioxide ($CO_2$)

The ratio of Carbon (C) to Oxygen (O) is $3:8$.

Atomic size

A measurement determined by the atomic radius.

Atomic radius

The distance from the nucleus to the outermost shell of an atom.

Nanometer ($nm$)

The unit used to measure atomic radius.