Elements are either metals or non-metals, and the two groups behave very differently. Typical metals are shiny, solid at room temperature (mercury is the one liquid exception) and have high melting points. They are good conductors of heat and electricity, they are malleable (they can be hammered into shape) and ductile (they can be pulled into wires). Typical non-metals are dull, are often gases or low melting point solids, and are poor conductors. Solid non-metals are brittle and shatter when hit. Graphite, a form of carbon, is an unusual non-metal because it does conduct electricity.
The chemical properties differ too. Metal atoms lose electrons to form positive ions, while non-metal atoms gain electrons to form negative ions or share electrons with other atoms.
Both types of element react with oxygen to form oxides. A metal such as magnesium burns to make magnesium oxide, and metal oxides are basic. If a metal oxide dissolves in water it forms an alkaline solution. Non-metals such as sulfur burn to make oxides like sulfur dioxide, and non-metal oxides are acidic. They form acidic solutions when they dissolve in water.