Warm Up 10-2-17 Element Al and Ar are in the same______ How many valence electrons are in Ca and Ga element? What’s wrong with this model of the carbon atom? https://www.youtube.com/watch?v=m55kgyApYrY Group 1 reactivity Demo - Magnesium burning Demo - battery and aluminum foil/gum wrapping Agenda -Turn in WS Homework -Notes Unit 3-2 -Lab Homework Finish lab conclusion Oct 4 – Test correction

Unit 3-2 Periodic Groups/Families

Classification Elements are classified as Metals Metalloids (semimetals) Nonmetals

Classification 77% of all the elements are metals

Metals Properties They are good conductors of electricity Most are ductile (can be stretched) and malleable (can be hammered or rolled into sheets) Can form alloys - solid or liquid mixtures of metals Talk about wires (landline, and internet) that are used as conductor – Expensive speakers with gold coating for better sounds (Beats by Dre headphones)

Check-In A = metals B = non metals C = metalloids Classify the following elements: 1.Na 2.H 3.Si

Main Groups Main Groups Main Groups Transition Groups Inner Transition Elements

Main Groups Use group number to find valence electrons

Cesium Alkali Metals Group 1 Highly reactive, (easily combine with other elements) reactivity increases going down a group Found in nature as compounds Potassium Sodium https://www.youtube.com/watch?v=m55kgyApYrY Alkali metals Lithium burns red and use in battery (lithium-ion) Electrolytes in sport drinks, potassium helps muscles contract

Alkaline Earth Metals Group 2 2nd most reactive group Give away 2 valence electrons calcium Calcium build bones Magnesium deficient can lead to depression. Cerebral spinal fluid (CSF) magnesium has been found low in treatment-resistant suicidal depression patients barium beryllium

Transition Metals d and f blocks Most lanthanides and actinides (f-block) are radioactive. Generally less reactive than alkali and alkaline earth metals Do not have identical outer electron configurations Common metals that a person will think of (copper, iron, gold, silver, zinc) https://www.youtube.com/watch?v=-n1pSHzdahc&t electric fence brainiac video Uranium ore

Halogens Group 17 Have 7 valence electrons and gain 1 electron in reactions (highly reactive) Reactivity decreases going down a group chlorine bromine iodine Halogens are oxidants (elements that grab electrons and mess up the cells in your body) Fluorine + carbon = teflon Halogens are non-metals React with metals to form salts Chlorine Gas

Noble Gases Group 18 Eight valence electrons makes them very stable (outermost energy level is full) Also called inert gases because of they are non-reactive Glow inside a gas-discharge lamp

Check-In Group 1 Group 2 Group 17 Group 18

Hydrogen Most common element in the universe Found in many organic compounds Flammable Fuel source for the sun (nuclear fusion) https://www.youtube.com/watch?v=7SLsFAAHVZs combustion of hydrogen gas Hindenburg 1937 going from Europe to New York (35 fatalities)

Assignments Summary: Why are noble gases stable and doesn’t react? And why group 1 & 17 are very reactive? Finish lab for homework