CHEM103 Chapter 2.1: 2.1 Elements, Compounds, and Mixtures - An Atomic Overview

• School: University of Alberta
• Department: Chemistry
• Course: CHEM103
• Professor: John Veinot

Document Summary

2. 1 elements, compounds, and mixtures: an atomic overview. Matter can be classified into 3 types: elements, compounds, mixtures. Elements and compounds are the 2 kinds of substances: a substance is matter whose composition is fixed. Mixtures are not substances b/c they have a variable composition. Elements: the simplest type of matter with unique physical and chemical properties. It consists of only one kind of atom therefore cannot be broken down into a simpler type of matter. Each element is unique b/c the properties of its atoms are unique. In nature, most elements exist as populations of atoms, either separated or in contact with each other, depending on the physical state. Several elements occur in molecular form: a molecule is an independent structure of two or more atoms bound together. E. g. oxygen occurs in air as diatomic molecules. Compounds: consists of 2 or more different elements that are bonded chemically.