1. PERIODICITY

3. Don’t have to write out the entire electron configuration.Don’t have to write out the entire electron configuration. There is a short-cut:There is a short-cut: –Keeps focus on valence electrons –An atom’s inner electrons are represented by the symbol for the nearest noble gas with a lower atomic number. Don’t have to write out the entire electron configuration.Don’t have to write out the entire electron configuration. There is a short-cut:There is a short-cut: –Keeps focus on valence electrons –An atom’s inner electrons are represented by the symbol for the nearest noble gas with a lower atomic number. K: [Ar]4s 1 Electron Configurations

4. For the element Phosphorus -- 15 electrons 1s 2 2s 2 2p 6 3s 2 3p 3 [Ne]P: Must be a Noble gas (One just before Element) Electron Configurations 3s 2 3p 3

5. Let’s do a couple more: Ba:[Xe] 6s 2 Hg:[Xe] V:[Ar] 4s 2 Electron Configurations 4f 14 5d 10 3d 3

7. Exceptions to the order of filling

8. The chemistry of an atom occurs at the set of electrons called valence electronsThe chemistry of an atom occurs at the set of electrons called valence electrons The valence electrons are electrons in an atom’s highest energy level.The valence electrons are electrons in an atom’s highest energy level. –For the Group – A elements, it is the outermost s & p e - of the atom. –Specifically the 2 s electrons + 6 p electrons (octet electrons) The arrangement of the valence e - lead to the element’s properties.The arrangement of the valence e - lead to the element’s properties. The chemistry of an atom occurs at the set of electrons called valence electronsThe chemistry of an atom occurs at the set of electrons called valence electrons The valence electrons are electrons in an atom’s highest energy level.The valence electrons are electrons in an atom’s highest energy level. –For the Group – A elements, it is the outermost s & p e - of the atom. –Specifically the 2 s electrons + 6 p electrons (octet electrons) The arrangement of the valence e - lead to the element’s properties.The arrangement of the valence e - lead to the element’s properties. Electron Configurations

11. 70 elements had been discovered by the mid-1800’s, but until Dmitri Mendeleev, no one had a come with a way to organize the elements.70 elements had been discovered by the mid-1800’s, but until Dmitri Mendeleev, no one had a come with a way to organize the elements. –Mendeleev came up with the first working system of filing the elements. He listed the elements in columns in order of increasing atomic mass, and then put columns together that were similarHe listed the elements in columns in order of increasing atomic mass, and then put columns together that were similar 70 elements had been discovered by the mid-1800’s, but until Dmitri Mendeleev, no one had a come with a way to organize the elements.70 elements had been discovered by the mid-1800’s, but until Dmitri Mendeleev, no one had a come with a way to organize the elements. –Mendeleev came up with the first working system of filing the elements. He listed the elements in columns in order of increasing atomic mass, and then put columns together that were similarHe listed the elements in columns in order of increasing atomic mass, and then put columns together that were similar History of the Periodic Table

13. Mendeleev left gaps in the table since there were no current elements that seemed to fit those spotsMendeleev left gaps in the table since there were no current elements that seemed to fit those spots –Those elements were eventually discovered and they fit perfectly into an open spot. The 1 st scientist that set the table in order of atomic number was Henry MoseleyThe 1 st scientist that set the table in order of atomic number was Henry Moseley Mendeleev left gaps in the table since there were no current elements that seemed to fit those spotsMendeleev left gaps in the table since there were no current elements that seemed to fit those spots –Those elements were eventually discovered and they fit perfectly into an open spot. The 1 st scientist that set the table in order of atomic number was Henry MoseleyThe 1 st scientist that set the table in order of atomic number was Henry Moseley History of the Periodic Table

14. The modern PT is arranged by increasing atomic numberThe modern PT is arranged by increasing atomic number –Increases from left to right, and top to bottom This establishes the periodic lawThis establishes the periodic law –When the elements are arranged in order of increasing atomic #, there is a periodic repetition of their phys & chem properties The modern PT is arranged by increasing atomic numberThe modern PT is arranged by increasing atomic number –Increases from left to right, and top to bottom This establishes the periodic lawThis establishes the periodic law –When the elements are arranged in order of increasing atomic #, there is a periodic repetition of their phys & chem properties History of the Periodic Table

17. An element’s properties can go hand in hand with electron arrangementAn element’s properties can go hand in hand with electron arrangement We can use an element’s location on the PT to predict many properties.We can use an element’s location on the PT to predict many properties. –Atomic radius –Electron affinity –Electronegativity –Ionization energy –Ionic Size An element’s properties can go hand in hand with electron arrangementAn element’s properties can go hand in hand with electron arrangement We can use an element’s location on the PT to predict many properties.We can use an element’s location on the PT to predict many properties. –Atomic radius –Electron affinity –Electronegativity –Ionization energy –Ionic Size Periodic Properties

18. The radius of an atom is defined by the edge of its last energy level.The radius of an atom is defined by the edge of its last energy level. –However, this boundary is fuzzy An atom’s radius is the measured distance between the nuclei of 2 identical atoms chemically bonded together - divided by 2.An atom’s radius is the measured distance between the nuclei of 2 identical atoms chemically bonded together - divided by 2. The radius of an atom is defined by the edge of its last energy level.The radius of an atom is defined by the edge of its last energy level. –However, this boundary is fuzzy An atom’s radius is the measured distance between the nuclei of 2 identical atoms chemically bonded together - divided by 2.An atom’s radius is the measured distance between the nuclei of 2 identical atoms chemically bonded together - divided by 2. Periodic Properties

19. As we examine atomic radius from left to right across the PT we see a grad- ual decrease in atomic size.As we examine atomic radius from left to right across the PT we see a grad- ual decrease in atomic size. –As e - are added to the s and p sublevels in the same energy level, they are gradually pulled closer to the highly positive nucleus The more e - ’s in the atom the less dramatic this trend looksThe more e - ’s in the atom the less dramatic this trend looks As we examine atomic radius from left to right across the PT we see a grad- ual decrease in atomic size.As we examine atomic radius from left to right across the PT we see a grad- ual decrease in atomic size. –As e - are added to the s and p sublevels in the same energy level, they are gradually pulled closer to the highly positive nucleus The more e - ’s in the atom the less dramatic this trend looksThe more e - ’s in the atom the less dramatic this trend looks Periodic Properties

22. The change in atomic radii across the PT is due to e - shielding or to the effective nuclear chargeThe change in atomic radii across the PT is due to e - shielding or to the effective nuclear charge –As we move across the PT we are adding e - into the same gen- eral vol. in which case they will shield or interact with each other (repulsion) The change in atomic radii across the PT is due to e - shielding or to the effective nuclear chargeThe change in atomic radii across the PT is due to e - shielding or to the effective nuclear charge –As we move across the PT we are adding e - into the same gen- eral vol. in which case they will shield or interact with each other (repulsion) Periodic Properties

23. –We are also adding protons into the nucleus which increases the p + -e - interaction (attraction) So the nucleus gains strength while the e - aren’t gaining much distance, so the atom is drawn in closer and closer to the nucleus.So the nucleus gains strength while the e - aren’t gaining much distance, so the atom is drawn in closer and closer to the nucleus. –Decreasing the overall radius of the atom –We are also adding protons into the nucleus which increases the p + -e - interaction (attraction) So the nucleus gains strength while the e - aren’t gaining much distance, so the atom is drawn in closer and closer to the nucleus.So the nucleus gains strength while the e - aren’t gaining much distance, so the atom is drawn in closer and closer to the nucleus. –Decreasing the overall radius of the atom Periodic Properties

26. How does the size of an atom change when electrons are added or removed?How does the size of an atom change when electrons are added or removed? As an Atom loses 1 or more electrons (becomes positive), it loses a layer therefore, its radius decreases. Periodic Properties

27. How does the size of an atom change when electrons are added or removed?How does the size of an atom change when electrons are added or removed? As an Atom gains 1 or more electrons (negative), it fills its valence layer, therefore, its radius increases. Periodic Properties

29. Elements in a group tend to form ions of the same charge.Elements in a group tend to form ions of the same charge. –Modeled by electron configurations. Elements in a group tend to form ions of the same charge.Elements in a group tend to form ions of the same charge. –Modeled by electron configurations. [Ar] 4s Loses 1 electron Loses 1 electron Wants a full set of e - [Ar] 4s K: Periodic Properties

30. [He] Gains 2 electrons Gains 2 electrons Wants a complete set O: 2s 2 2p 4 Periodic Properties

31. Periodic Trend of Ionic Charges

32. The Transition Elements are almost unpredictable, and sometimes have more than one possible charge -- due to d orbitals --

33. Tend to lose electrons to become positive Tend to gain electrons to become negative

34. Another periodic trend on the table is ionization energy (a.k.a. potential)Another periodic trend on the table is ionization energy (a.k.a. potential) –Which is the energy needed to remove one of an atoms e - s. –Or a measure of how strongly an atom holds onto its outermost e - s. If the e - s are held strongly the atom will have a high ionization energyIf the e - s are held strongly the atom will have a high ionization energy Another periodic trend on the table is ionization energy (a.k.a. potential)Another periodic trend on the table is ionization energy (a.k.a. potential) –Which is the energy needed to remove one of an atoms e - s. –Or a measure of how strongly an atom holds onto its outermost e - s. If the e - s are held strongly the atom will have a high ionization energyIf the e - s are held strongly the atom will have a high ionization energy Periodic Properties

38. The ionization energy is generally measured for one electron at a timeThe ionization energy is generally measured for one electron at a time You can also measure the amount of energy needed to reach in and pluck out additional electrons from atoms.You can also measure the amount of energy needed to reach in and pluck out additional electrons from atoms. –There is generally a large jump in energy necessary to remove additional electrons from the atom. Periodic Properties

39. the amount of energy required to remove a 2p e – (an e - in a full sublevel) from a Na ion is almost 10 times greater than that required to remove the sole 3s e -

40. There is simply not enough energy available or released to produce an Na 2+ ion to make the compnd NaCl 2There is simply not enough energy available or released to produce an Na 2+ ion to make the compnd NaCl 2 –Similarly Mg 3+ and Al 4+ require too much energy to occur naturally. Chemical formulas should always describe compounds that can exist naturally the most efficient way possibleChemical formulas should always describe compounds that can exist naturally the most efficient way possible Periodic Properties

42. Another periodic trend dealing with an e- is electron affinityAnother periodic trend dealing with an e- is electron affinity –Which is a measure of the ability of an atom to attract or gain an electron. Atoms that tend to accept an e - are those that tend to give a neg. charge.Atoms that tend to accept an e - are those that tend to give a neg. charge. –The closer to a full outer shell an atom has, the higher the affinity (more neg. the measurement) Another periodic trend dealing with an e- is electron affinityAnother periodic trend dealing with an e- is electron affinity –Which is a measure of the ability of an atom to attract or gain an electron. Atoms that tend to accept an e - are those that tend to give a neg. charge.Atoms that tend to accept an e - are those that tend to give a neg. charge. –The closer to a full outer shell an atom has, the higher the affinity (more neg. the measurement) Periodic Properties

46. An atoms ability to lose an e - or gain an e - can be used to understand the Octet RuleAn atoms ability to lose an e - or gain an e - can be used to understand the Octet Rule Octet Rule: atoms tend to gain, lose, or share electrons in order to acquire a full set of valence electrons.Octet Rule: atoms tend to gain, lose, or share electrons in order to acquire a full set of valence electrons. –2 e - in the outermost s sublevel + 6 e – in the outermost p sublevel= a full valence shell An atoms ability to lose an e - or gain an e - can be used to understand the Octet RuleAn atoms ability to lose an e - or gain an e - can be used to understand the Octet Rule Octet Rule: atoms tend to gain, lose, or share electrons in order to acquire a full set of valence electrons.Octet Rule: atoms tend to gain, lose, or share electrons in order to acquire a full set of valence electrons. –2 e - in the outermost s sublevel + 6 e – in the outermost p sublevel= a full valence shell Periodic Properties

49. Electronegativity is a key trend.Electronegativity is a key trend. –It reflects the ability of an atom to attract electrons in a chemical bond. –F is the most electronegative element and it decreases moving away from F. Electronegativity correlates to an atom’s ionization energy and electron affinityElectronegativity correlates to an atom’s ionization energy and electron affinity Electronegativity is a key trend.Electronegativity is a key trend. –It reflects the ability of an atom to attract electrons in a chemical bond. –F is the most electronegative element and it decreases moving away from F. Electronegativity correlates to an atom’s ionization energy and electron affinityElectronegativity correlates to an atom’s ionization energy and electron affinity Periodic Properties

54. INCREASES INCREASES BOILING POINT & MELTING POINT VS. ATOMIC NUMBER

57. On the PT, only the elements through 92 are naturally occurringOn the PT, only the elements through 92 are naturally occurring Elements are created through a process that took place in stars before our solar system came into beingElements are created through a process that took place in stars before our solar system came into being –This process is called stellar nucleosynthesis. On the PT, only the elements through 92 are naturally occurringOn the PT, only the elements through 92 are naturally occurring Elements are created through a process that took place in stars before our solar system came into beingElements are created through a process that took place in stars before our solar system came into being –This process is called stellar nucleosynthesis. Elemental Origins

58. Stars form when clouds of dust and hydrogen gas condenseStars form when clouds of dust and hydrogen gas condense –As this material condenses, pressure builds and temperatures reach millions of degrees –The energy that is produced help stars live for billions of years The principle source of stellar energy is nuclear fusionThe principle source of stellar energy is nuclear fusion Stars form when clouds of dust and hydrogen gas condenseStars form when clouds of dust and hydrogen gas condense –As this material condenses, pressure builds and temperatures reach millions of degrees –The energy that is produced help stars live for billions of years The principle source of stellar energy is nuclear fusionThe principle source of stellar energy is nuclear fusion Elemental Origins

59. Fusion occurs when the nuclei of 2 or more atoms join together, to form the nucleus of a larger atomFusion occurs when the nuclei of 2 or more atoms join together, to form the nucleus of a larger atom Typically – 2 H nuclei combine to produce one He nucleus.Typically – 2 H nuclei combine to produce one He nucleus. Fusion occurs when the nuclei of 2 or more atoms join together, to form the nucleus of a larger atomFusion occurs when the nuclei of 2 or more atoms join together, to form the nucleus of a larger atom Typically – 2 H nuclei combine to produce one He nucleus.Typically – 2 H nuclei combine to produce one He nucleus. Elemental Origins

61. This is a type of nuclear rxnThis is a type of nuclear rxn The mass of helium nucleus formed in the fusion process is slightly less than the mass of the four hydrogen nuclei that went into it.The mass of helium nucleus formed in the fusion process is slightly less than the mass of the four hydrogen nuclei that went into it. This small amount of “missing” mass is converted to energy according to Einstein’s eqn E=mc 2This small amount of “missing” mass is converted to energy according to Einstein’s eqn E=mc 2 This is a type of nuclear rxnThis is a type of nuclear rxn The mass of helium nucleus formed in the fusion process is slightly less than the mass of the four hydrogen nuclei that went into it.The mass of helium nucleus formed in the fusion process is slightly less than the mass of the four hydrogen nuclei that went into it. This small amount of “missing” mass is converted to energy according to Einstein’s eqn E=mc 2This small amount of “missing” mass is converted to energy according to Einstein’s eqn E=mc 2 Elemental Origins

63. The mass of combining nuclei supplies the enormous energy that stars use to shineThe mass of combining nuclei supplies the enormous energy that stars use to shine –Nuclear fusion is not only the princ- iple source of energy for stars, but also the process by which elements heavier than H are created. –The sun converts about 400 million tons of H into He every second The mass of combining nuclei supplies the enormous energy that stars use to shineThe mass of combining nuclei supplies the enormous energy that stars use to shine –Nuclear fusion is not only the princ- iple source of energy for stars, but also the process by which elements heavier than H are created. –The sun converts about 400 million tons of H into He every second Elemental Origins

64. Other fusion rxns occur, depending on the mass of the star, the temp. of the star, & the stage of its developmntOther fusion rxns occur, depending on the mass of the star, the temp. of the star, & the stage of its developmnt –2 He-4 atoms might combine to form Be-8; 1 He-4 & 1 Be-8 can fuse to form C-12 When a star uses up all of the ele- ments that fuel its fusion, the star is no longer stable, & it dies in a last great explosionWhen a star uses up all of the ele- ments that fuel its fusion, the star is no longer stable, & it dies in a last great explosion Other fusion rxns occur, depending on the mass of the star, the temp. of the star, & the stage of its developmntOther fusion rxns occur, depending on the mass of the star, the temp. of the star, & the stage of its developmnt –2 He-4 atoms might combine to form Be-8; 1 He-4 & 1 Be-8 can fuse to form C-12 When a star uses up all of the ele- ments that fuel its fusion, the star is no longer stable, & it dies in a last great explosionWhen a star uses up all of the ele- ments that fuel its fusion, the star is no longer stable, & it dies in a last great explosion Elemental Origins

65. –The elements that were formed within the star are flung into space When planets condense from this material, they take up the rich array of elements in the debris.When planets condense from this material, they take up the rich array of elements in the debris. –Elements heavier than Fe were created by supernovas –The elements that were formed within the star are flung into space When planets condense from this material, they take up the rich array of elements in the debris.When planets condense from this material, they take up the rich array of elements in the debris. –Elements heavier than Fe were created by supernovas Elemental Origins

67. On earth, which is considered a closed system, most elements are found in biogeochemical cycles.On earth, which is considered a closed system, most elements are found in biogeochemical cycles. –Elements are recycled through processes that keeps the amount of elements on earth constant. –The “big six” cycles important for life are carbon, water, oxygen, phosphorus, nitrogen, sulfur Elemental Origins

78. The first artificial isotope was created in 1919The first artificial isotope was created in 1919 –  particles were being used to produce elements in the lab Homemade Elements Scientists were taking  particles and colliding them with nitrogen atomsScientists were taking  particles and colliding them with nitrogen atoms This led to the fusion of nuclei to form a synthetic isotope of oxygenThis led to the fusion of nuclei to form a synthetic isotope of oxygen

79. This was the first incident in which one element was transformed into another in a lab.This was the first incident in which one element was transformed into another in a lab. Today, scientists change one element into another by bombarding nuclei with various small particlesToday, scientists change one element into another by bombarding nuclei with various small particles –Protons, neutrons, alpha particles, and beta particles (fast moving electrons) Homemade Elements

80. These “nuclear bullets” react with the nuclei they are aimed at forming iso- topes of naturally occurring elementsThese “nuclear bullets” react with the nuclei they are aimed at forming iso- topes of naturally occurring elements Numerous synthetic elements are created with this methodNumerous synthetic elements are created with this method –All of the elements with atomic #s greater than 92 but less than 101 were created with this process Homemade Elements

81. The particles must be moving at extremely fast speeds and with a huge amount of energy in order to actually fuse rather than simply bouncing off of one anotherThe particles must be moving at extremely fast speeds and with a huge amount of energy in order to actually fuse rather than simply bouncing off of one another –A device called a “Particle Accelerator” is used to accomplish this task Homemade Elements

82. Elements with atomic # 101 & greater have been created by a colliding whole atoms rather than particles.Elements with atomic # 101 & greater have been created by a colliding whole atoms rather than particles. –To make the bigger atoms, special accelerators hurl entire atoms at one another Nobelium was created by crashing together Ca and PbNobelium was created by crashing together Ca and Pb Homemade Elements

83. The discovery of element 109 has been thoroughly verified and acceptedThe discovery of element 109 has been thoroughly verified and accepted –It is extremely unstable –Only 3 atoms of element 109 have ever been produced –They only existed for a short time (.0034 seconds) Homemade Elements

85. Scientists are hoping to discover other heavier atoms that might be more stable, because of the nature of their nucleiScientists are hoping to discover other heavier atoms that might be more stable, because of the nature of their nuclei The “atom smashers” they plan to use are technological marvels, and there are only a few in the worldThe “atom smashers” they plan to use are technological marvels, and there are only a few in the world Homemade Elements

86. An accelerator is a linear or circular device that is used to increase the velocity of charged particlesAn accelerator is a linear or circular device that is used to increase the velocity of charged particles When the particle has been given a very high velocity and thus a very high energy, it is aimed at a target material.When the particle has been given a very high velocity and thus a very high energy, it is aimed at a target material. Homemade Elements

88. The collision can help scientists discover new info. About the nucleus, & sometimes create a heavier atom.The collision can help scientists discover new info. About the nucleus, & sometimes create a heavier atom. Homemade Elements

89. A typical accelerator is circular in shapeA typical accelerator is circular in shape Particles are accelerated by electric fields in several loca- tions around the ring.Particles are accelerated by electric fields in several loca- tions around the ring. The particle’s path is confined to the ring by huge magnets.The particle’s path is confined to the ring by huge magnets. Homemade Elements

90. The greater the energy of the collision between the accelerated particles with the target.The greater the energy of the collision between the accelerated particles with the target. The more scientists can learn about the structure and the behavior of the nucleusThe more scientists can learn about the structure and the behavior of the nucleus Homemade Elements