The Periodic Table. Shows the known elements, their symbols, atomic numbers, and atomic masses. Lead 82 Pb metal solid. Atomic number.

Transcription

1 PERIODIC TABLE

2 The Periodic Table Shows the known elements, their symbols, atomic numbers, and atomic masses Atomic number Lead 82 Pb metal solid Symbol Atomic mass

3 The Periodic Table The element s position tells us if it is a metal, non-metal, or metalloid Over the years many attempts were made to create a table that would show the relationship between the size of the atom and its properties.

4 Dmitri Mendeleev Russian Chemist Made a card for every known element He pinned all cards to a wall by increasing atomic mass Then rearranged the cards into rows and columns based on patterns in their properties Lead 82 Pb metal solid

5 Mendeleev s table Properties of elements repeat at definite or periodic intervals. This pattern became known as the PERIODIC TABLE

6 MORE ON MENDELEEV He left gaps in his periodic table because not all elements had been discovered The gaps have been filled in over the years as new elements have been discovered

7 MEET THE MODERN PERIODIC TABLE The Periodic Table is a system for organizing the elements into columns and rows BrainPOP: Periodic Table You Tube: the new periodic table song: https: // v=vgvqkccfwnu (click on an element)

8 OTHER SCIENTISTS Berzelius designed a system to name the elements Volta invented the battery which allowed us to classify metals as conductors and non-metals as non-conductors Dalton - his atomic theory reminds us that atoms of different elements have a specific mass based on the number of protons, neutrons, and electrons

9 VOLTA S BATTERY

10 Classifying Elements The Periodic Table is organized into metals, nonmetals, and metalloids, shown with color. See page in your textbook or the following websites: S ID METALS LO AL ET M NON-METALS

11 PROPERTIES OF... Metals Solids at room temperature, but mercury is liquid Shiny lustre Good conductors of heat and electricity Malleable and ductile Non-metals Some gases at Metalloids Solids at room room temp., some solids, bromine is liquid Not very shiny Poor conductors of heat and electricity Brittle, not ductile temp. Can be shiny or dull May conduct electricity, poor conductors of heat Brittle, not ductile

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13 PERIODS = horizontal rows Periods are numbered 1-7 Period number = number of electron shells

14 GROUPS = FAMILIES = vertical columns Groups are numbered 1-18 Elements in the same family have similar chemical properties The main property for you to understand is REACTIVITY (how easily an element reacts with another element)

15 Alkaline metals Group 1 React rapidly when exposed to air and water Have only 1 outer electron to lose and become stable

16 Alkaline Earth metals Group 2 Also quite reactive Have 2 outer electrons to lose to become stable

17 Halogens Group 17 Most reactive non-metals Need to gain 1 electron to be stable

18 Noble gases Group 18 Chemically calm (unreactive) Can be excited by electricity to make colors in discharge tubes but do not change chemically

19 Reactivity Atoms want 8 electrons in their outer shell (called the valence shell and valence electrons) Atoms without 8 valence electrons react with other atoms by sharing, giving up, or taking electrons to fill their valence shell

20 Atomic Structure Lithium Valence shell Valence electron: in valence shell 3 electrons 1 valence electron (group 1) 2 shells (period 2)

21 Reactivity in Families Alkali metals: 1 valence electron, the most reactive elements, can easily give up that electron Alkali earth metals: 2 valence electrons, the next most reactive Halogens: 7 valence electrons, also very reactive they easily accept 1 electron Noble gases: very unreactive, have 8 electrons in their valence shell

22 Atomic number REMEMBER Lead 82 Pb metal solid Symbol Atomic mass Atomic # = # protons An element is defined by the # of protons it has Atomic mass= # protons + # neutrons Standard atomic form Complete Topic 2.4 worksheet

23 REVIEW QUESTIONS (ANSWER ALL 7) 1. Identify the name, atomic number, and mass number of: a. b. c. K P N 2. List the main properties of metals? 3. How did Mendeleev contribute to chemistry? 4. Identify the element and write the standard atomic notation for: a. b. c. Group 2, Period 3 Group 14, Period 2 Group 18, Period 4

24 REVIEW QUESTIONS CONT D Draw a Bohr model with 1 valence electron, name the atom Explain why halogens are more reactive than noble gases. Which has more electrons, an atom of aluminum or an atom of phosphorus?

25 ELEMENT SUPERHERO PROJECT Create a superhero using the properties of your element. Use the template or create your own.

26 ELEMENT SUPERHERO REQUIREMENTS 1. Superhero s name 2. At least 2 Fun Facts about your element superhero such as: common uses or compounds, date discovered or by whom, where it is found 3. Describe your superhero s talents or abilities using at least 3 chemical properties such as: Atomic number, atomic mass, melting/boiling point, density, state at room temperature, metal/non-metal/metalloid 4. Draw a Bohr model diagram showing the # of shells with electrons, and write the # of protons, and neutrons in the nucleus

27 ELEMENT SUPERHERO MARKING RUBRIC Name: Superhero s Name 2 Fun Facts 3 Properties within description Accurate Bohr diagram Total /

28 Superhero Description Fun Facts Bohr Model

29 Superhero Description Fun Facts Bohr Model

30 Superhero Description Fun Facts Bohr Model