1. Discriminating Between Elements, Compounds, and Mixtures Init 9/8/2016 By Daniel R. Barnes

2. Instructor, please have some volunteers read the following out loud to the class: Sodium (Na) is a soft, grey metal that you can cut with a knife. When you put sodium in water, it sizzles, catches on fire, and may even explode. Chlorine (Cl 2 ) is a poisonous green gas. It was used as a chemical weapon in World War I. Sodium chloride (NaCl) is a brittle, white solid that dissolves peacefully in water. Sodium chloride is so safe that there’s usually a container of it on every table of every restaurant in the whole country.

3. Think-pair share: Q: Is salt an element, a compound, or a mixture. Why? You have two minutes to think, write, and discuss with your table. THINK PAIR SHARE GO!

4. SOME GOOD ANSWER MATERIAL: Sodium chloride is a compound because it is made of two or more elements that are bonded to each other chemically. Sodium chloride’s properties are drastically different from the properties of the elements that make it up. There is always one sodium atom for every one chlorine atom. In NaCl, they always occur in a 1:1 ratio.

5. O = oxygen atom H = hydrogen atom Na = sodium atom Cl = chlorine atom N = nitrogen atom O O = oxygen molecule Cu = copper atom Sn = tin atom

6. O O O O O O O O O O O O Oxygen gas: An element? A compound? A mixture?

7. Hydrogen gas: An element? A compound? A mixture? H H H H H H H H H H H H H H H H

8. O Water: An element? A compound? A mixture? H H H H H H H H H H H H O O H O O H O O H O H

9. Sn Tin: An element? A compound? A mixture?

10. O O O O Air: An element? A compound? A mixture? N N NN N N N N N N N N NN NN

11. Cu Copper: An element? A compound? A mixture?

12. N O O O O Nitrous oxide: An element? A compound? A mixture? N N N N N N N NNN N N O O O N

13. Chlorine gas: An element? A compound? A mixture? Cl

14. Sn Cu Sn Cu Sn Cu Sn Cu Sn Cu Sn Cu Sn Cu Sn Cu Sn Cu Sn Bronze: An element? A compound? A mixture?

15. NaClNaClNaClNaClNaClNa ClNaClNaClNaClNaClNaCl NaClNaClNaClNaClNaClNa ClNaClNaClNaClNaClNaCl NaClNaClNaClNaClNaClNa ClNaClNaClNaClNaClNaCl NaClNaClNaClNaClNaClNa ClNaClNaClNaClNaClNaCl Sodium chloride (table salt): An element? A compound? A mixture?

16. O H H H H H H H H H H H H O O H O O H O O H O H Na Cl Na Cl Na Cl Na ClNa Cl Na Cl Na Salt water: An element? A compound? A mixture?