1. What are these lists of?
They are the ingredients to shampoo (above) and a meal bar (right)

2. What are these ingredients?
Are these even real things?
Where did they come from?

3. Elements, Compounds, and Molecules

4. We have only 26 letters in our alphabet.
But we can combine these 26 simple letters in a variety of ways to form tens of thousands different English words.

5. The periodic table of elements has 118 different “letters”
We can combine these elements to form millions of different substances.
Including these substances:

6. Atoms can combine
Two or more atoms can chemically combine by sharing, taking away, or giving away electrons
Oxygen O2
Water H2O
Salt NaCl

7. Molecule When the atoms combine, they form a molecule.
A molecule is made of two or more atoms which have chemically combined.

8. Molecules might be made of atoms of the same element.

9. Or molecules might be made of two or more atoms of different elements
We call these compounds.
Compounds are molecules made of two or more different elements

10. Is it a molecule? Is it a compound? Is it both?
Molecule and a compound!
Molecule!
Molecules and compounds review. All elements are at least 21 years old in this video.

11. Review:
Are all of these substances molecules?
Yes! They all have two or more atoms chemically combined.
Are all of these substances compounds?
No- only the bottom row has two or more atoms of different elements, which make them compounds

12. Molecules can come in many shapes and sizes!
Nylon- used in many plastics

13. Largest molecule ever made by humans!

14. We are made of molecules!
DNA is made up of molecules called nucleotides.
Each nucleotide contains a phosphate group, a sugar group and a nitrogen base.
The four types of nitrogen bases are adenine (A), thymine (T), guanine (G) and cytosine (C). 

15. Our DNA molecules are so large, they have to coil up in our chromosomes, which are found in the nucleus of every cell

16. Anti-social atoms
Some atoms don’t like to chemically combine, or bond, with other atoms.
This special group is called the Noble Gases and they are all found in the last column of the periodic table.

18. How can I tell what is in a molecule?
A formula unit will tell us:
What elements are in a molecule.
2. How many atoms of each element are in a molecule.

19. NaCl- a molecule of salt
Na- Sodium
Cl-Chlorine
A molecule of salt is made of one atom of sodium and one atom of chlorine.

20. H2O – a molecule of water H- Hydrogen O- Oxygen What does the 2 mean?
The number tells us how many atoms of the element there are.
The number is put after the element it is referring to as a subscript (low) number.
There are 2 Hydrogen atoms, and one oxygen atom in a molecule of water.

21. Can you tell what elements and how many are in this compound?

22. Salt- 1 Sodium atom and 1 Chlorine atom
Glucose- 12 Carbon, 22 hydrogen, 11 oxygen atoms
Vinegar- 2 carbon, 3 hydrogen, 2 oxygen atoms
Baking Soda- 1 sodium, 1 hydrogen, 1 carbon, 3 oxygen atoms

23. What elements? How many atoms?

25. Are you concerned about Dihydrogen Monoxide?

26. Mixtures
Mixtures occur when the atoms or molecules mix together, but do not chemically combine or bond.
Examples include: air, salt water, lemonade, salad dressing

27. The cruelest mixture EVER!

29. Mixture!
Element
Compound
Mixture!
Element!
Compound!

30. Match the picture to the categoryD B C E

31. Chemical Formula HW