1. Chemistry Review by Margaret Zulick

2. The Atom: makes up everything (living and nonliving) Made of – Protons (+) – Neutrons (0) – Electrons (-) 2 parts: – Nucleus - inside (protons and neutrons) – Electron Cloud - outside (electrons) Electrons in outer shell = Valence Electrons

3. Elements Atoms that have the same number of protons are the same element Also known as… – “A pure substance” – can’t be broken down All elements are displayed on the Periodic Table

5. The only option that is an element on the periodic table is Gold. All the other options are mixtures or compounds (combinations of other elements that could be broken down).

6. Periodic Table: organizes all elements Metals On the Left and in the middle Shiny (luster) Malleable Conducts heat & electricity

7. Periodic Table: organizes all elements Non - Metals On the Right Dull Brittle Bad conductors

8. Periodic Table: organizes all elements Metalloids On the Stairstep Semiconductors (computer chips) Mix of metals and nonmetals

9. Based on their location on the PT, determine whether the following elements are metals, metalloids or nonmetals. Fluorine (F) Potassium (K) Manganese (Mn) Silicon (Si) Nitrogen (N)

10. Based on their location on the PT, determine whether the following elements are metals, metalloids or nonmetals. Fluorine (F) - Nonmetal Potassium (K) - Metal Manganese (Mn) - Metal Silicon (Si) - Metalloid Nitrogen (N) - Nonmetal

11. The Periodic Table is organized! Periods  :left and right Groups: Up and down – Elements in the same group are similar – Alkali Metals: most reactive (Group 1) – Noble Gases: do not react (Group 18)

13. Nitrogen (N) and Phosphorus (P) are in the same group, so they are the most similar.

14. The Periodic Table is organized! Atomic Number = number of protons Symbol Element Name Atomic Mass

15. Bonds Atoms bond because they want a full outer shell – The closer they are to having a full shell, the more reactive they are (more likely to bond) Bonds hold atoms together to form a compound

16. When atoms of different elements bond, they form compounds Examples: 1. H + O  H 2 O Hydrogen + Oxygen  Water 2. Na + Cl  NaCl Sodium + Chlorine  Sodium Chloride Compounds are completely different than the elements that make them up!

17. Chemical Equations What starts the reaction (ingredients) What is made after the reaction Subscript: Tells us the number of atoms Coefficient: used to balance equations

18. Law of Conservation of Mass Mass can never be created nor destroyed Need the same number of atoms of each element on each side!

20. Mass or matter cannot be created nor destroyed!

22. Mass cannot be created nor destroyed. What you start with, you MUST end with!

23. To speed up a reaction… Add heat Add a Catalyst More surface area – smaller pieces are better than big pieces. X ✔

24. Mixtures When 2 or more compounds are mixed together, we call this a mixture. Ex. H 2 O and NaCl mixed together forms a salt water mixture 2 Types: – Homogeneous: The same throughout (ex. Lemonade/Koolaid) – Heterogeneous: NOT evenly mixed (ex. Salad: you see lettuce, peppers, tomatoes, salad dressing)

25. HomogeneousHeterogeneous

26. Solute vs. Solvent vs. Solution Solution = Homogeneous Mixture Solute: Solid that is dissolved – Ex. Koolaid Powder Solvent: Liquid the solid is dissolved into – Universal Solvent is WATER!

27. Concentration High Concentration: Lots of solute dissolved in solvent – Ex. LOTS of Koolaid powder in a little bit of water, makes it very strong and concentrated Low Concentration: Little bit of solute in solvent – Ex. Small amount of Koolaid in water makes it taste weak, low concentration

28. Chemical Change Cannot be undone Makes a BRAND NEW substance! 4 Signs: – Color Change – Formation of a gas – Formation of a precipitate (a solid) – Temperature Change

30. Physical Change Can be undone Does NOT change what the substance is Ex. Tearing a piece of paper Phase changes (solid to liquid, liquid to gas) – Ex. Melting ice into liquid water

32. Freezing Water = still water! = Physical Burning Coal = cannot undo this = Chemical

33. Exothermic Vs. Endothermic Exothermic: – Exo = OUT! Heat RELEASED = will feel warm Endothermic: – Endo = IN! Heat absorbed in = will feel cold Ex. Photosynthesis

34. pH Scale Scale of 0 to 14 Acids: Sour (ex. Orange Juice, Vinegar) pH between 0 and 7 Bases: Bitter (ex. Milk, detergent) pH between 7 and 14 Neutral pH is 7