ELEMENTS, COMPOUNDS AND MIXTURES KATINA PECK

3 CATEGORIES OF MATTER Elements Compounds Mixtures Cu H2OH2O Pizza

ELEMENTS Elements are the building blocks of matter. Cu Everything in the Universe is made from about 118 elements. Each element is made up of the same type of atoms.

COMPOUNDS Compounds are made up of two or more different elements. Compounds have different properties than the elements that make it up.

COMPOUNDS Each compound is represented by a formula.  H 2 O= 2 Hydrogen & 1 Oxygen, 2:1  CO 2= 1 Carbon & 2 Oxygen, 1:2  NaCl= 1 Sodium & 1 Chlorine 1:1 Chemically combined in a specific ratio. H2OH2O

COMPOUNDS Formulas are made of the symbols and a subscript number. The subscript is the number of atoms of that element. A coefficient tells us how many molecules there are. Coefficient Subscript

MIXTURE Most of the matter in the Universe is a compound or a mixture. A mixture is made of two or more substances that are not chemically combined. Substances in a mixture retain their properties.

MIXTURE Two types of mixtures: Heterogeneous  Substances in the mixture are easily distinguished.  Pizza, trail mix, Italian salad dressing Homogeneous  Two or more substances are uniformly mixed.  Salt water, the air we breath, soft drinks Heterogeneous Homogeneous

MOLECULE A molecule is formed when two or more atoms join together chemically. If the molecule is made of two atoms of the same element, it is called a diatomic atom.  Di- two  Atomic- atom  Two atoms  H 2  O 2

COMPARISON A molecule is formed when two or more atoms join together chemically. A compound contains at least two different elements. All compounds are elements, but not all elements are compounds.

SOLUTION A homogeneous mixture. Solute- the substance being dissolved. Solvent- the substance that dissolves a solute. Solubility- the amount of solute that will dissolve in a solvent. Solvent Solute Solution Solute

COLLOIDS A heterogeneous mixture that never settles. Example: Milk Scatters light

SUSPENSION A heterogeneous mixture that has particles that settle. Example: Italian salad dressing