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ENGAGE: The Element Song 1955. Click above!. The Periodic Table. Patterns and Trends. The Group Numbers on top for columns of “families.”. Group numbers are also related to the number of valence electrons. 1. 18. Increasing Atomic mass going down a group. 14. 13. 15. 16. 17. 2. 3.
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ENGAGE: The Element Song 1955 Click above!
The Periodic Table Patterns and Trends
The Group Numbers on top for columns of “families.” Group numbers are also related to the number of valence electrons. 1 18 Increasing Atomic mass going down a group 14 13 15 16 17 2 3 4 5 6 7 8 9 10 12 11 This is group 1 the alkali group.Families have similarbut not identical characteristics
Periods numbered down the side and form rows or “periods.” Increasing Atomic mass going across a period. 1 2 3 4 This is period number 3 which means it has3 energy levels. 5 6 7
Transition Metals Noble Gases Alkaline Earth Metals Halogens Nonmetals Alkali Metals Metalloids Mixed Group Metals Lanthanide Series Actinide Series
Sizes of Atoms and Ions • Consider a simple diatomic molecule. • The distance between the two nuclei is called the bond distance. • If the two atoms which make up the molecule are the same, then half the bond distance is called the covalent radius of the atom.
Periodic Trends in Atomic Radii • down a group, the atoms become larger. • across a period, atoms become smaller. Larger radius
Periods represent the number of rings or what scientists call “energy levels” of electrons. Energy Level 3: Na, Mg, Al, Si, P, S Cl & Ar
Metals What type of elements are these?
Metals, Nonmetals, and Metalloids • Metals • Metallic character refers to the properties of metals (shiny or lustrous, malleable and ductile, oxides form basic ionic solids, and tend to form cations in aqueous solution). • Metallic character increases down a group. • Metallic character decreases across a period. • Metals give up electrons easily, forming positive ions.
Metals + e- e- + e- + + + e- e- + e- React lose electrons to nonmetals; become a positive ion (cation) Al increase in reactivity Au Pt Au, Pt: Are exceptions they are very unreactive! Fr Increase in reactivity
Metals Melting and boiling points Al Increase Au Pt Fr Increase temperature of MP and BP
Nonmetals What type of elements are these?
Nonmetals e- e- e- e- e- e- e- e- e- React Gain electrons from metals; become a negative ion (anion), or share with nonmetals. Reactivity
Nonmetals Increase Temperature of MP & BP. Melting and boiling points Increase
Metalloids What type of elements are these?
Metalloids e- + e- Metalic and nonmetalic properties. React Gain or Lose electrons; become a cation or anion.