Presentation on theme: "Periodicity Objectives:"— Presentation transcript:
1 Periodicity 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
3 Periodic 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
4 Modern Periodic Table What are the columns called? Answer: Groups What are the horizontal rows called?Answer: PeriodsLabel groups & rows on your periodic table!!
5 Modern 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)
6 Metals 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.
7 Groups 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.
8 Both 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.
9 Group 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
10 Nonmetals 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
11 Halogens: 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.
12 Metalloids 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.
13 Assignment Label the following on your blank periodic table: Groups & periodsRepresentative elementsTransition elementsMetals: alkali metals, alkaline earth metals, transition metals, and inner transition metalsNonmetalsHalogensNoble gasesmetalloids