Elements, Compounds and Mixtures

__Element:_ A substance that is composed of very small particles called atoms * $_Atoms$ :__ the most basic form of matter
__Molecules:__ Formed by atoms of elements that chemically combine (which we show by having them touch)
__Diatomic element:__ Atoms that are two of the same kind * Oxygen is found as a diatomic element in nature. Therefore, it’s written as O₂ * Carbon does not exist as a diatomic element in nature. If it did, it would be written as C₂
__7 Naturally Occurring Diatomics:__ H₂, O₂, N₂, Cl₂, Br₂, I₂, F₂
__Compound:__ A molecule consisting of 2 or more different elements that are chemically combined * Ex: 1 carbon atom +1 oxygen atom = CO (carbon monoxide) * Ex 2: 1 oxygen atom + 1 carbon atom + 1 oxygen atom = CO₂ (carbon dioxide)
__A MIXTURE of Elements:__ All in the same container, but are NOT touching each other, making them physically combined * Ex: A mixture of Carbon and Oxygen in the same container, not touching each other
__A MIXTURE of Compounds:__ Physically combined in the same container * Ex: Carbon monoxide and carbon dioxide physically combined in the same container
__A MIXTURE of Elements & Compounds:__ All in the same container, not touching, physically combined * Ex: Carbon, Oxygen, Carbon Monoxide, and Carbon Dioxide all in the same container, physically combined