What do the blue arrows mean?
Mixtures can be sorted using physical processes into substances. Compounds can be separated using chemical processes into elements
Last word on compounds “A compound is a substance that is made of two of more simpler substances and can be broken down into those simpler substances.” ( Elements cannot…) Example : The decomposition of water; also called the electrolysis of water. (Phil Morrison video) https://www.youtube.com/watch?v=buFe-CyQctQ
12/4/15 Please write a heading: Observing Chemical Properties “As a candle burns, new substances are formed.” What are the new substances? Water + Carbon dioxide Old substances? Candle wax + oxygen
“ A chemical property is any ability to produce a change in the composition of matter.” (text) In other words, new substances are formed!
2 Chemical Properties Flammability – the ability of a substance to burn in the presence of oxygen Examples Lighter fluid, paper, candle wax (paraffin.) 2. Reactivity – how readily a substance combines chemically with other substances. Oxygen is a highly reactive element. (copper bar; silver spoon) Nitrogen is less reactive.
Oxygen is reactive. Nitrogen is unreactive.
3 ways to make new substances in your kitchen… (Recognizing Chemical Changes) 1. Banana ripens Color change new color, new substance 2. “volcano experiment” baking soda +vinegar Production of a gas bubbles without heat, new substance
3. Chunky (curdled) milk Formation of a Precipitate Solid from liquids, new substance