1. Welcome to Science Class! Before the Bell… Warm-Up Be sure to copy learning target and homework into agenda. We will be discussing the NOTES you wrote for homework about elements and compounds!

2. Today, we will be creating brace maps On a blank sheet of paper, use the following compounds to create a brace map. SubstanceCompound Element # of Atoms Hydrogen 2 Water H 2 O Oxygen 1

3. Today, we will be creating brace maps On a blank sheet of paper, use the following compounds to create a brace map. SubstanceCompound Element # of Atoms Hydrogen 2 Water H 2 O Oxygen 1

4. chemical symbols. Elements are pure substances that are represented by chemical symbols. Some elements are represented by one letter Can you find elements in your periodic table that are represented by one letter? Others are represented by two letters. Can you find elements in your periodic table that are represented by TWO letters? PAUSE! READ THIS!

5. Sometimes one element can have two letters, so don’t get confused! Hint : each element will have at least one capital letter

6. SubstanceCompound Element # of Atoms Hydrogen2 Water H 2 O Oxygen 1HOMEWORK! 1.C 6 H 12 O 6 : sugar 2.CaCl 2 : calcium chloride 3.NaHCO 3 : sodium bicarbonate (baking soda) 4.CO 2 : carbon dioxide 5.Mg(OH) 2 : magnesium hydroxide (milk of magnesia) 6.C 2 H 5 OH: ethyl alcohol 7.HCl: hydrochloric acid 8.KMnO 4 : potassium permanganate 9.NH 3 : ammonia 10.FeS 2 : pyrite (fool’s gold)

7. MORE SubstanceCompound Element # of Atoms Sodium1 Sodium Hydrogen 1 BicarbonateNaHCO 3 Carbon1 Oxygen3

8. SubstanceCompound Element # of Atoms Magnesium1 Magnesium Oxygen 2 Hydroxide Mg(OH) 2 Hydrogen2 MORE When there is a parenthesis like this (OH) 2, then the subscript changes the elements inside the parentheses. That is why there are 2 atoms of Oxygen AND 2 atoms of Hydrogen