4.3: “Trends in the Periodic Table” 1. A ____________ is a ___________________ change in a particular direction. a. Understanding a trend among ____________ lets you make ________________ about their _________________ behavior. b. These trends in ________________ can be explained in terms of __________________ ______________________. 2. A ____________(or family) is a _________________ column in the periodic table. a. A _______________ is a horizontal _____________ in the periodic table. 3. Ionization energy: the _______________ required to remove an _________________ from an atom or ion. 4. Trend: Ionization energy __________________ as you move down a _______________ and ______________ left to right across a ___________. 5. Why does ionization energy decrease as you move down a group? a. Each element has more occupied energy ______________ than the element __________ it has. b. The ___________________ electrons are farthest from the ______________ in elements near the _____________ of a group and require ____________ energy to remove. c. As you move down a group, each successive element contains more _____________in the energy levels between the _______________ and the __________________ electrons. This is called electron shielding. d. Electron Shielding: the ___________________ of the attractive force between a positively charged _______________ and its outermost ________________ due to the cancellation of some of the __________________ charge by the __________________ charges of the inner electrons. 6. Why does ionization energy increase as you move left to right across a period? a. From one element to the next in a _______________, the number of _____________ and the number of ________________ increase by 1 each. b. The additional ______________ increases the nuclear _______________ (more + charge in nucleus) c. A _________________ nuclear charge more _________________ attracts the outer electrons in the same energy level, but the electron-shielding effect from inner-level electrons remains the _____________. d. ______________ energy is required to remove an electron because the ___________________ force on them is _________________. 7. The exact size of an ____________ is hard to determine because the _______________ cloud has no clear-cut ____________. a. In addition, the physical and chemical state of an atom can __________ the size of the _______________ _____________. b. One method for calculating the __________ of an atom involves calculating the _______________ ____________. c. Bond Radius: ___________ the distance from center to ______________ of 2 like atoms that are ________________ together. 8. Trend: Atomic radius ____________ as you move down a _______________ and decreases left to right across a _______________. 9. Why does atomic radius increase as you move down a group? a. As you move from one ________________ down to the next in a _____________, another principle ____________ level is filled with electrons. b. The addition of another level of electrons _____________ the size, or atomic radius, of an _____________. c. Because of _______________ _________________, the effective nuclear charge acting on the outer electrons is almost constant as you move down a _______________. 10. Why does atomic radius decrease as you move left to right across a period? a. As you move from left to right across a _______________, each atom has one more _____________ and one more ____________ than the atom before it has. b. All additional electrons go into the ____________ principle energy levels – no ________________ are being added to the _____________ levels. c. Electron shielding does ____________ play a role as you move ____________ a period. d. As the nuclear charge ___________ across a period, the effective nuclear charge acting on the outer electrons also _______________, pulling the electrons closer and closer to the ______________. 11. Why does the atomic radius level out after group _________? a. As the outermost ______________ are pulled closer to the ____________, they also get closer to one another and the _______________ between these electrons gets stronger. b. Finally, a point is reached where the electrons will _________ come closer to the ____________ because they would be too close to each other and the atomic radii _______________ off. 12. Atoms often _______________ to one another to form a _________________. a. These bonds can involve ____________________ electrons, but not all atoms ___________ electrons _________________. b. Electronegativity: a measure of the ability of an atom in a chemical compound to attract ______________. c. The atom with the __________________ electronegativity will _____________ the electrons more _____________ than the other atom will. It will HOG the electron! 13. _______________ is the biggest electron ____________ of all. a. It has the ___________ electronegativity value of ________ of all the elements on the periodic table. 14. Trend: Electronegativity ____________as you move down a _____________ and ______________ left to right across a ________________. 15. Why does electronegativity decrease as you move down a group? a. As you move down a ___________, another principle _____________ level is _______________ with electrons. b. The _______________ between the ______________ and the ____________ energy levels ________________. c. The ________________ distance means that the ______________ cannot attract ________________ electrons as strongly. 16. Why does electronegativity increase as you move across a period? a. As you move across a _________________, each atom has one more _____________ and one more ____________ - in the ______________ principle energy level – than the atom before it has. b. Electron shielding does __________ change as you move across a ____________ because no _________________ are being added to the _____________ levels. c. The effective nuclear charge _____________ across a period. (more + charge in nucleus) d. As this increases, ________________ are attracted much more _______________, resulting in an increase in ___________________. 17. Electron affinity: the ____________ change that occurs when a ____________ atom gains an _______________. a. Electron affinity is different from _____________________ because electronegativity is a measure of the atom’s attraction for an ____________ when the atom is ____________ to another atom. 18. Trend/Why: Electron affinity tends to_____________ as you move down a ___________ because of ___________ ___________. a. Electron affinity tends to ___________ as you move across a ___________ because of increasing ____________ ___________. 19. Trend: Melting and boiling points reach 2 different __________ as d and p ___________ fill with _________________. 20. Why do melting and boiling points reach 2 different peaks? a. From left to right across period 6, the melting points and boiling points at first _______________. b. As the number of _______________ in each element increases, ______________ bonds between atoms can form. c. Stronger bonds mean __________ energy is needed for melting and boiling to occur. d. Near the middle of the d-block of elements, the melting and boiling points reach a _______________. 21. As more _________________ are added, they begin to form ____________ within the d orbitals. a. Because of the decrease in unpaired _________________, the bonds that the atoms can form with each other become ______________. b. As a result, these elements have ________________ melting and boiling points 22. As you move past mercury in period 6, the melting points and boiling points again begin to ____________ as electrons are now added to the ______________ and the same _________ in _______________ and _______________ points are seen. a. The ______________ gases have __________ bonding forces between atoms because they have no ______________ electrons. b. Their melting and boiling points are unusually _____________.