2. Chemistry Letters & Words

3. Chemistry Sentences If chemical formulas are the words in the language of chemistry, then chemical equations are the chemical sentences. Each sentence summarizes the details of a particular chemical reaction. Chemical reactions entail the breaking and forming of chemical bonds, causing atoms to be rearranged into new substances.

4. Products vs. Reactants Reactants: the original starting substances in a chemical reaction. Left Side! Products: the new substance or substances are formed from the rearrangement of the reactants. Right Side! 2 H2 O2 H2O 2

5. Balancing Equations Lets Atom Inventory this chemical equation: N2 + H2  NH3 N2 + H2  NH3 Where do we need to insert some numbers to make sure there are an even amount on the products and reactants side? Remember we cant touch the suscript numbers! 3 2

6. Diatomic Molecules Most uncombined elements in chemical equations are represented as single atoms. Cu………Ag…………Na……….K………….W A handful of elements are diatomic molecules. They exist as two bonded atoms of the same element. GEN-U-INE Diatomics serves as a good memory device for all common diatomic molecules. The names of all diatomic elements ending in GEN or INE are diatomic molecules. Hydrogen  H 2 Chlorine  Cl 2 Fluorine  F 2 Nitrogen  N 2

7. Electrical Nature of Matter How do the atoms in molecules stick together to form bonds? Static cling and dryer sheets Shocked when walking across carpet or rug Balloons rubbed together Positve + Positve = repel Negative + Negative = repel Postive + Negative = attract What are these positives and negatives called? Protons – Positvely charged in the nucleus Neutrons-Neutral charged in the nucleus Electrons- Negatively charged around the nucleus

8. Independent Work Work on Day Sheet # 22 which will re-enforce balancing equations or taking atom inventory. It will also help with finding elements and naming