Presentation on theme: "Periodicity Objectives:"— Presentation transcript:
1Periodicity Objectives: AHSGE Reading Discern organizational patterns.Other AOD C.3.2 Recognize periodic trends of elements, including the number of valence electrons, atomic size, and reactivity.Periodicity
3Periodic LawDmitri Mendeleev’s periodic table had the elements arranged in order of increasing mass.There is a periodic repetition of chemical and physical properties of the elements when they are arranged by increasing atomic number
4Modern Periodic Table What are the columns called? Answer: Groups What are the horizontal rows called?Answer: PeriodsLabel groups & rows on your periodic table!!
5Modern Periodic TableRepresentative elements: elements in the A groups (1A-8A)“the main group”Possess a wide range of physical and chemical propertiesTransition elements: elements in the B groups (1B-8B)
6Metals Describe some properties of metals. Metals: Generally shinyMost are solid at room temperatureGood conductors of heat and electricityDuctile and malleableMost group A and all group B elements are metals.
7Groups 1A and 2A, EXCEPT HYROGEN, are metals. The other elements in group 1A are called alkali metals.Reactive & Readily combine with group 6 and 7 elements.Group 2A elements are alkaline earth metals.Contain a pair of electrons in their outermost shell.
8Both groups 1A and 2A are highly reactive (1A more so). Why would group 1A be more reactive than group 2A?Answer: Group 2A has a FILLED s orbital, but group 1A’s s orbital is only half-filled, so that electron is still looking for a partner to hook up with.
9Group B elements:Transition metals: located on the main body of the periodic tableInner transition metals: the 2 rows located along the bottom of the periodic table
10Nonmetals Describe some properties of nonmetals. Nonmetals: Generally gases or brittle, dull-looking solidsPoor conductors of heat or electricityThe ONLY nonmetal that is a liquid at room temperature is bromine.Located in the upper right portion of the periodic table
11Halogens: Group 7A elements; highly reactive Noble gases: Group 8A; extremely Unreactive.Why are group 8A elements unreactive?Answer: Their outer valence shell is filled, so they have no need to pair up with anyone else.
12Metalloids Have properties of both metals and nonmetals. Stair-step down from boron to astatine and germanium to polonium.They separate the metals and nonmetals on the periodic table.
13Assignment Label the following on your blank periodic table: Groups & periodsRepresentative elementsTransition elementsMetals: alkali metals, alkaline earth metals, transition metals, and inner transition metalsNonmetalsHalogensNoble gasesmetalloids