Chemical-Bonds_080223.pptxdiscover bonds

bonds and all

1. ION - any atom with more or less electrons that it is supposed to have - An electrical attraction between two oppositely charged atoms or groups of atoms. - Happens when an atom of a nonmetal takes one or more electrons from an atom of a metal so both atoms end up with eight valence electrons IONIC BONDING

2. OCTET RULE - The octet rule says that atoms can become stable by having eight electrons in their outer energy level, as shown in the noble gas, Neon, (or two electrons in the case of some of the smallest)

3. - Metals will have few valence electrons - These will come off

4. Metals will have few valence electrons These will come off Forming positive ions

5. Nonmetals will have many valence electrons. They will gain electrons to fill outer shell

6. metal with nonmetal + ion - ion Cation anion

7. Predicting Oxidation Number or Charge from Periodic Table metals lose e - form cations oxidation # group 1A lose 1 +1 charge 1 + group 2A lose 2 +2 charge 2 + group 3A lose 3 +3 charge 3 + group 4A lose 4 +4 charge 4 +

8. Non-metals gain e - form anions oxidation # group 7A gain 1 -1 charge 1 - group 6A gain 2 -2 charge 2 - group 5A gain 3 -3 charge 3 -

9. Neutral atoms come near each other. Electron(s) are transferred from the Metal atom to the Non-metal atom. They stick together because of electrostatic forces, like magnets.

10. STEPS IN WRITING IONIC BOND Determine the oxidation numbers for the two elements or ions. Write the chemical symbols in the correct order, with the metal ion first and write the oxidation numbers as superscripts. Crisscross the numbers only—not the charge signs—writing the oxidation number of one element as a subscript for the other. Check the formula by calculating the total positive and negative charges and confirming that the total charge on the compound is zero.

11. REDOX REACTIONS

12. Redox stands for reduction-oxidation reaction, which is a common phenomenon in terms of chemical reaction. Usually and almost everyday, majority of the chemical reactions taking place in the earth’s crust is a redox reaction. The main difference between oxidation and reduction be established as:

13. OXIDATION- involves the loss of electrons - results in an increase in the oxidation number of the atom or ion REDUCTION- involves the gain of electrons - results in the decrease in the oxidation number of the atom or ion

14. A reducing agent is the substance that is oxidized while an oxidizing agent is the substance that is reduced in a chemical reaction. Example: Inorganic Redox 4Fe ₍ₛ₎ + 3O₂₍g₎ → 2FeO3₍ₛ₎ Organic Redox C₆H₁₂O₆₍ₛ₎ → 6CO₂ ₍g₎ + 6H₂O₍ₗ₎

15. REMEMBER: - An atom is a neutral particle, thus the charge of a substance in its atomic/ elemental state is always zero - the total charge of a compound is always equal to zero - increase or decrease in oxidation number is caused by the migration of electrons

16. Steps in recognizing REDOX reaction mechanism: Assign oxidation numbers to each element found in the reaction - elements are assigned with an oxidation number of zero - compounds have total charge of zero. For binary compounds, the charge of the metallic elements can be found in references such as periodic tables and text books - for multivalent element, the oxidation number of each substances in the compound is determined algebraically

17. 2. Noted which substances changes its oxidation state. Apply the following rules: - if there is a lost of electron/s, the element is oxidized and the substance is the reducing agent - if there is a gain of electron/s, the element is reduced and the substance is the oxidizing agent

18. This is simply remembered as LEORA and GEROA: LEORA: Lost of Electrons; Oxidized; Reducing Agent GEROA: Gain of Electrons; Reduced; Oxidizing Agent

19. The reducing and oxidizing agents are those that are in the reactant side. EXAMPLE: Identify the oxidizing and reducing agents in the reaction; Zn ₍ₛ₎ + AgNO ₃₍ₐ₎ → Zn(NO₃)₂₍ₐ₎ + Ag₍ₛ₎