Science 9 Quarter 2 Reviewer PDF

**SCIENCE 9 QUARTER 2 REVIEWER** \- The energy of an electron decreases when it goes nearer to the nucleus. **Answer this:** \- What is the electron configuration of Calcium? \- What is the correct orbital diagram of a Nitrogen element with 7 electrons? ---- -- ---- -- ------- -- ------- -- -...

**SCIENCE 9 QUARTER 2 REVIEWER** \- The energy of an electron decreases when it goes nearer to the nucleus. **Answer this:** \- What is the electron configuration of Calcium? \- What is the correct orbital diagram of a Nitrogen element with 7 electrons? ---- -- ---- -- ------- -- ------- -- ------- 1s 2s 2p~x~ 2p~y~ 2p~z~ ---- -- ---- -- ------- -- ------- -- ------- **Valence electrons** - the outermost electrons which are directly involved in chemical bonding. Energy levels maximum number of electrons 1^st^ Energy Level 2 -------------------- ---- 2^nd^ Energy Level 8 3^rd^ Energy Level 18 4^th^ Energy Level 32 **Types of Chemical Bonding** Ionic Bonding -- transfer of electrons - Non-metals + Metals Covalent Bonding -- sharing of electrons -- Non-metals + Non-metals Metallic Bonding -- sea of electrons - Metals + Metals Element Groups in the Periodic Table Example: Sodium (Na) and Lithium (Li) belongs to Group 1, therefore they end with s^1^ and has 1 valence electron Electron jumps from higher to lower energy level produces colored light. **Chemical Bonding** -- atoms form a bond with one another to: \- become stable \- attain electronic configuration of the noble gas nearest to it \- to form compounds Complete transfer of electron/s in Ionic Bonding - the electronegativity difference of the two combining elements must be greater than 1.9 Examples of Ionic Bonding: NaCl, NaF, KCl Covalent Bonding examples:  CH~4~ - Methane Diamond -- Carbon HCl **Properties of Ionic Compounds** - - - **Properties of Covalent Molecular Compounds** - - - **Properties of Metals** - - - **Ions** -- atoms that carry a positive or negative charge - - **Group IA or Group I** \- Group in periodic table that will have a charge of +1 when it becomes an ion \- Forms a +1 ion Example: Sodium, Lithium **Group 3** \- Group in periodic table that will have a charge of +3 when it becomes an ion Example: Aluminum \+ 1 -- lost 1 electron +2 -- lost 2 electrons \+ 3 -- lost 3 electrons \- 3 -- gained 3 electrons \- 2 -- gained 2 electrons -1 -- gained 1 electron **HYDROCARBONS - ALKANES** ---------------------------- ----------- ----------- ---------------------------------- **Name** **Phase** **Condensed Structural Formula** Methane Gas CH~4~ Ethane Gas C~2~H~6~ CH~3~CH~3~ Propane Gas C~3~H~8~ CH~3~CH~2~CH~3~ Butane Gas C~4~H~10~ CH~3~CH~2~CH~2~CH~3~ **Uses of Carbon Compounds** *Hydrocarbons* -- used as fuel. Example: Methane, Butane *Hydroxyl Group* -- Isopropyl Alcohol, Ethyl Alcohol -- used in wounds *Carbonyl Group* -- Formalin, Acetone -- used in preserving Ethyne -- used as artificial ripening agent Kerosene -- used as paint thinner to remove paint Gasoline -- volatile and flammable **Metals** Aluminum -- used form making cooking utensil because it is a good conductor of heat Mercury - liquid at room temperature. **Metallic Bonding** - Isopropyl Alcohol -- used as cleaner, fuel, and disinfectant Methane -- used as fuel Acetone -- used to remove nail polish High Flammable hydrocarbons -- LPG and Kerosene **ALKANES** -- Hydrocarbons with single bonds Examples: Methane, Ethane, Propane, Butane, Pentane, Octane - **ALKENES** -- Hydrocarbons with double bonds Examples: Pentene, Ethene, Butene Pentene **Hydrocarbons** - - - Conductivity and Malleability - two properties that make metals a good choice to use as a wire in electronics metals are good electrical conductors because metal ions form a lattice surrounded by a "sea" of free electrons