POST TRANSITION METALS

Transcription

1 Hydrogen is considered to be a group on its own POST TRANSITION METALS NON METALS NOBLE GASSES HALOGENS TRANSITION METALS ALKALI METALS ALKALINE EARTH METALS LANTHANIDES ACTINIDES SEMI METALS

2 TRENDS OF THE PERIODIC TABLE Chemistry 11 Atomic Theory

3 WHICH ONE OF THE FOLLOWING ARE BIGGER? 1.Li or Na 2.Cs or Rb 3.F or Cl 4.Pb or Si

4 WHICH ONE OF THE FOLLOWING IS BIGGER? 1. Na or Mg 2. Na or Cl

5 TRENDS OF THE PERIODIC TABLE We will be discussing the following trends 1. Atomic Radius 2. Ionization Energy 3. Electronegativity 3 factors are discussed when explaining above trends 1. Nuclear Charge 2. Shielding Electrons 3. Number of Shells

6 NUCLEAR CHARGE LEFT TO RIGHT Across The Periodic Table vatomic # increases = # of protons increase (more +ve charges) Electrons experience pull force from the positive protons in the nucleus. OVERALL Pull on electrons due to nuclear charge INCREASES

7 NUCLEAR CHARGE TOP TO BOTTOM Down The Periodic Table Table v Atomic # increases = # of protons increase (more +ve charge) OVERALL Pull on electrons due to nuclear charge INCREASES

8 SHIELDING ELECTRONS 5P 6N Boron

9 SHIELDING ELECTRONS Outer Electrons being blocked by the inner electrons from nuclear charge 5P 6N What are shielding electrons? Electrons in the lower shells that block the pull of the protons. Campfire Analogy If someone is between you and the fire, you feel less heat. Boron 2 Shielding electrons

10 SHIELDING ELECTRONS LEFT TO RIGHT Across The Periodic Table OVERALL Number of Shielding electrons STAY THE SAME 4P 5N 9P 10N Beryllium 2 Shielding electrons Fluorine 2 Shielding electrons

11 SHIELDING ELECTRONS TOP TO BOTTOM Down The Periodic Table Table 10 Shielding electrons 18 Shielding electrons OVERALL Number of Shielding electrons INCREASES

12 NUMBER OF SHELLS LEFT TO RIGHT Across The Periodic Table Number of shells stay the SAME going across

13 NUMBER OF SHELLS LEFT TO RIGHT Down The Periodic Table Table Number of shells INCREASE going down

14 ATOMIC RADIUS

15 ATOMIC RADIUS LEFT TO RIGHT Across The Periodic Table Nuclear Charge Increases More protons pull electrons closer Atom is SMALLER Number of Shells Stays the same in the same period NO CHANGE Shielding Electrons Stay the same in the same period NO CHANGE OVERALL Atomic Radius DECREASES Going Across

16 ATOMIC RADIUS TOP TO BOTTOM Down The Periodic Table Table Nuclear Charge Increases More protons pull electrons closer Atom is SMALLER Number of Shells Increase going down Atom is LARGER Shielding Electrons Increases More electrons blocking the pull of outer electrons. Atom is LARGER OVERALL Atomic Radius INCREASES Going Down

17 Atomic Radius Increases Table Atomic Radius Decreases

18 EXERCISE What is the largest atom in period 4? Potassium What is the largest and the smallest atom in group 2? Largest Radium Smallest Beryllium Which is larger? F or B? Ba or Be? Sr or P? B Ba Sr

19

20 Open the refrigerator, put the giraffe in and close the door Open the refrigerator, take out the giraffe put in the elephant and close the door The Elephant You swim across. All the crocodiles are attending the animal conference

21 JIGSAW ACTIVITY Sitting in groups, you will be assigned one of three cards (Nuclear Charge, Shielding Electrons, and Number of Shells. Try to come up with answers to the questions individually and then discuss with group members.

22 JIGSAW ACTIVITY Find two other classmates that have different cards than yours. Take turns to explain your answers. Do the backside of Periodic Table Trends worksheet

23 JIGSAW ACTIVITY In your groups come up with the following conclusions OVERALL Atomic Radius INCREASES or DECREASES going across? OVERALL Atomic Radius INCREASES or DECREASES going down?

24 ATOMIC RADIUS IONS CATIONS (+ve) Lose electrons: Interelectron repulsion (repulsion between electrons) decreases. Cation is SMALLER than its Atom ANIONS (ve) Gain electrons: Interelectron repulsion (repulsion between electrons) increases. Anion is LARGER than its Atom

25 IONIZATION ENERGY It ALWAYS requires energy to remove an electron from an atom!!! We ae breaking the electron s attraction towards the nucleus. DEFINITION Ionization energy Energy required to remove an electron from the outer shell

26 IONIZATION ENERGY LEFT TO RIGHT Across The Periodic Table Predict how nuclear charge, shielding electrons and number of shells would influence ionization energy going across the periodic table. Explain your answer.

27 IONIZATION ENERGY LEFT TO RIGHT Across The Periodic Table Nuclear Charge Increases More protons pull electrons closer Harder to remove an electron Ionization Energy INCREASES Number of Shells Stays the same in the same period NO CHANGE Shielding Electrons Stay the same in the same period NO CHANGE OVERALL Ionization Energy INCREASES

28 IONIZATION ENERGY LEFT TO RIGHT Down The Periodic Table Table Predict how nuclear charge, shielding electrons and number of shells would influence ionization energy going down the periodic table. Explain your answer.

29 IONIZATION ENERGY TOP TO BOTTOM Down The Periodic Table Table Nuclear Charge Increases More protons pull electrons closer. Harder to remove an electron. Ionization Energy INCREASES Number of Shells Increases Electrons move farther away from the nucleus. Easier to remove an electron. Ionization energy DECREASES Shielding Electrons Increases More electrons block the pull of outer electrons. Easier to remove an electron. Ionization Energy DECREASES OVERALL Ionization Energy DECREASES

30 Ionization Energy Decreases Table Ionization Energy Increases

31 EXERCISE What atom has the highest Ionization Energy? He Which has the lowest Ionization energy? Fe or B? B Ba or Ba 2+? Ba Sr or P? Sr

32 ELECTRONEGATIVITY DEFINITION Ability of an atom to attract an electron from another atom. If an atom has high electronegativity, it strongly attracts electrons from other atoms and might even remove the electron completely.

33 ELECTRONEGATIVITY LEFT TO RIGHT Across The Periodic Table Predict how nuclear charge, shielding electrons and number of shells would influence electronegativity going across the periodic table. Explain your answer.

34 ELECTRONEGATIVITY LEFT TO RIGHT Across The Periodic Table Nuclear Charge Increases More protons, attract electrons more. Atom is strong! Easier to remove electron from another atom Electronegativity INCREASES Shielding Electrons Stay the same in the same period NO CHANGE Number of Shells Stays the same in the same period OVERALL Electronegativity INCREASES NO CHANGE

35 ELECTRONEGATIVITY LEFT TO RIGHT Down The Periodic Table Table Predict how nuclear charge, shielding electrons and number of shells would influence electronegativity going down the periodic table. Explain your answer.

36 ELECTRONEGATIVITY TOP TO BOTTOM Down The Periodic Table Table Nuclear Charge Increases More protons attract electrons more. Atom is Strong! Easier to pull an electron from another atom. Electronegativity INCREASES Number of Shells Increases Electrons are farther away from the proton. Atom is weak! Harder to pull electron from another atom. Electronegativity DECREASES. Shielding Electrons Increase Block the charge of protons. Atom is weaker. Harder to pull electron from another atom. Electronegativity DECREASES OVERALL Electronegativity DECREASES

37 Electronegativity Decreases Table Electronegativity Increases

38 MEASURING ELECTRONEGATIVITY We use Pauling Scale to quantify electronegativity. Highest electronegativity (value of 4) is assigned to Fluorine. Values range down to Cs and Fr, which are the lease electronegative atoms (value of 0.7)

39

40 ELECTRONEGATIVITY AND IONIZATION ENERGY If an atom has high electronegativity, it will also have a high ionization energy! An atom that is strong, will not give away its electron easily!!!

41 HOMEWORK