1. Chapter 15 Structure of the Periodic Table

2. patterns in the Periodic Table  elements are arranged in order of increasing proton number; proton number increases from left to right across the Table  consists of:  elements are arranged in order of increasing proton number; proton number increases from left to right across the Table  consists of: the Periodic Table o periods: horizontal rows numbered 1, 2, 3, etc o groups: vertical columns labelled I, II, III, etc o transition elements o lanthanides & actinides (not tested) o periods: horizontal rows numbered 1, 2, 3, etc o groups: vertical columns labelled I, II, III, etc o transition elements o lanthanides & actinides (not tested)

3. patterns in the Periodic Table the Periodic Table

4.  elements in the same group have the same number of valence electrons; form the same type and number of bonds patterns in the Periodic Table electronic structures and chemical bonds ElementSymbol Electron Configuration lithiumLi2.1 sodiumNa2.8.1 potassiumK2.8.8.1 carbonC2.4 siliconSi2.8.4  elements in the same group have similar chemical properties, and will react with other elements/compounds in the same way  Na + H 2 O  NaOH + H 2  K + H 2 O  KOH + H 2  elements in the same group have similar chemical properties, and will react with other elements/compounds in the same way  Na + H 2 O  NaOH + H 2  K + H 2 O  KOH + H 2

5. patterns in the Periodic Table electronic structures and chemical bonds  elements on the left side of the Periodic Table lose all their outer shell electrons to form positive ions  those on the right side gain electrons to fill their outer shells with eight electrons like a noble gas, forming negative ions  elements on the left side of the Periodic Table lose all their outer shell electrons to form positive ions  those on the right side gain electrons to fill their outer shells with eight electrons like a noble gas, forming negative ions ElementNaMgAlAl SiPSClCl Ar Group Number IIIIIIIVVVIVII0 Formula of Ion Na + Mg 2+ A l 3+ -P 3- S 2- Cl - -

6.  metals are found on the left side of the Periodic Table; non- metals are found on the right side  dividing line in the Periodic Table separates the metals and the non-metals  across each period from left to right, elements change from metals to non-metals o across each period, oxides of elements change from basic to acidic; elements near the dividing line form amphoteric oxides o in general, elements with small number of valence electrons are metals; elements with large number of valence electrons are non-metals  metals are found on the left side of the Periodic Table; non- metals are found on the right side  dividing line in the Periodic Table separates the metals and the non-metals  across each period from left to right, elements change from metals to non-metals o across each period, oxides of elements change from basic to acidic; elements near the dividing line form amphoteric oxides o in general, elements with small number of valence electrons are metals; elements with large number of valence electrons are non-metals patterns in the Periodic Table metals and non-metals

7. patterns in the Periodic Table metals and non-metals

8.  proton number increases down a group  physical properties of elements change down a group  proton number increases down a group  physical properties of elements change down a group patterns in the Periodic Table changes in a group  For example: Group I metals’ melting and boiling points decrease down the group However, Group VII halogens’ melting and boiling points increase down the group  For example: Group I metals’ melting and boiling points decrease down the group However, Group VII halogens’ melting and boiling points increase down the group

9. using the Periodic Table predicting properties  properties of elements can be predicted from knowledge of other elements in the same group Element Molecular Formula chlorineCl2Cl2 bromineBr 2 iodineI2I2  For example: Chlorine reacts with sodium to form NaCl Iodine, Bromine and fluorine also reacts with sodium to form NaI, NaBr and NaF In reverse, we can also predict how potassium will react with chlorine Qn: Predict the chemical formula of caesium iodide  For example: Chlorine reacts with sodium to form NaCl Iodine, Bromine and fluorine also reacts with sodium to form NaI, NaBr and NaF In reverse, we can also predict how potassium will react with chlorine Qn: Predict the chemical formula of caesium iodide

10. Element Proton Number Melting Point (°C) Boiling Point (°C) fluorine9-220-188 chlorine17-101-35 bromine35-759 iodine53114184 astatine85-- using the Periodic Table predicting properties  properties of elements change from a group, with increasing proton number

11. outer shell electrons metals are arranged in order of Periodic Table protonnumber group period non-metals a vertical set of elements is a are on the right side of horizontal row is a are on the left side of increases down a groupnumber have many is the same as the number of have the same number of have few from left to right across a change from metals to non-metals