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www.stao.ca Student Activity Snakes and Ladders Gaming Instructions 1. Randomly select a package from your teacher and place your die and player token within it. This package includes all materials needed for the game, including the board itself, and Snakes/Ladders/Regular envelopes containing question/answer cards. 2. Play the board game with a partner. 3. Each person rolls the die. The one who rolls the highest number starts the game. 4. The first person rolls the die and must first answer a “regular” question in order to move forward from Start. 5. The next person rolls the die and repeats step 4. 6. Continue taking turns rolling the die and answering a question from the correct envelope. 7. If you arrive at the bottom of a ladder, you can only climb up it if you correctly answer a difficult Ladder question. Place used “ladder” cards below card pile only if the questions were correctly answered. If not, the next person who lands at the base of a ladder has an opportunity to answer a previously attempted but incorrectly answered question. 8. If you arrive at the top of a snake, you must correctly answer an easy Snake question in order to avoid sliding down it. Place used “snake” cards below card pile only if the questions were correctly answered. If not, the next person who lands at the top of a snake has an opportunity to answer a previously attempted but incorrectly answered question. 9. If you are on a spot other than at the bottom of a ladder or the top of a snake, then you must answer a moderately difficult Regular question in order to move forward on the board the correct number of spaces according to what you roll from the die. 10. Once a winner is declared, you have the option of either playing the same game again (consider this option if a number of questions were left unanswered and/or answered incorrectly) or swap board games with another group that has finished its game. Be sure to place all items back into the envelope (including player tokens and die) before exchanging envelopes between groups. 11. HAVE FUN! www.stao.ca Snakes (easy) — Question 1 Snakes (easy) — Answer 1 What element has a higher electronegativity, Sr or Br? Br has a higher electronegativity than Sr. Snakes (easy) — Question 2 Snakes (easy) — Answer 2 Which type of element can generally lose electrons most easily? Metals, nonmetals, or metalloids? Metals can generally lose electrons most easily. Snakes (easy) — Answer 3 Define Effective Nuclear Charge. Effective Nuclear Charge (ENC) is the apparent nuclear charge as experienced by the outermost electrons of an atom when shielding by the innershell electrons is taken into account. Snakes (easy) — Question 4 Snakes (easy) — Answer 4 Determine which of the following elements you would expect to have the lowest first ionization energy Li, Cs, H, He, Ba Of the elements listed, Cs has the lowest first ionization energy. Snakes (easy) — Question 3 Snakes and Ladders – Page 2 www.stao.ca Snakes (easy) — Question 5 Snakes (easy) — Answer 5 Which element has more electronegativity, Kr or As? As has more electronegativity than Kr. Snakes (easy) — Question 6 Snakes (easy) — Answer 6 Fill in the blank: When moving from left to right across a period, atomic radius ____________ . When moving from left to right across a period, atomic radius decreases. Snakes (easy) — Question 7 Snakes (easy) — Answer 7 Fill in the blank: Ionization energy ____________ decreases when going down a group. Ionization energy decreases when going down a group. Snakes (easy) — Question 8 Snakes (easy) — Answer 8 Which group of elements typically has comparatively higher electron affinities, metals or non-metals? Non-metals. Snakes and Ladders – Page3 www.stao.ca Snakes (easy) — Question 9 Snakes (easy) — Answer 9 What element on the periodic table has the smallest atomic size? Helium has the smallest atomic size. Snakes (easy) — Question 10 Snakes (easy) — Answer 10 What element on the periodic table has the largest atomic size? Francium has the largest atomic size. Snakes (easy) — Question 11 Snakes (easy) — Answer 11 Which element has the greatest electronegativity? Fluorine. Snakes (easy) — Question 12 Snakes (easy) — Answer 12 Which atom has the larger atomic radius, Li or K? K because it is below Li in the group. Snakes and Ladders – Page 4 www.stao.ca Snakes (easy) — Question 13 Snakes (easy) — Answer 13 Which atom, Ca or Ni, has the larger atomic radius? Ca because it is more towards the left of the periodic table and atomic radius decreases from left to right. Snakes (easy) — Question 14 Snakes (easy) — Answer 14 Which atom, Ga or B, has the larger atomic radius? Ga because it is below B in the group. Snakes (easy) — Question 15 Snakes (easy) — Answer 15 Which atom, O or C, has the larger atomic radius? C because it is more towards the left than O in the period. Snakes (easy) — Question 16 Snakes (easy) — Answer 16 Define nuclear charge. Total positive charge associated with the nucleus, based on the number of protons present. Snakes and Ladders – Page 5 www.stao.ca Snakes (easy) — Question 17 Snakes (easy) — Answer 17 Which element has the smallest atomic radius: Na, Li, or Be? Be has the smallest atomic radius because it is more towards the right of the lower period. Snakes (easy) — Question 18 Snakes (easy) — Answer 18 Which is larger, P 3- or S 2-? P 3- Snakes (easy) — Question 19 Snakes (easy) — Answer 19 What is atomic radius? Atomic radius is one-half the distance between the nuclei of two atoms of the same element, bondedor not bonded. Snakes (easy) — Question 20 Snakes (easy) — Answer 20 Arrange this set of elements in order of increasing ionization energy: F, Cl, Br Br, Cl, F with F being the element with the highest ionization energy. Snakes and Ladders – Page 6 www.stao.ca Ladder (hard) — Answer 1 Ladder (hard) — Question 1 Which is larger, F 1- or F and why? F 1- is larger because the nuclear charge is unchanged, but due to an extra electron, the electron-electron repulsion increases causing the electron cloud to enlarge as would be required to minimize this repulsion. Ladder (hard) — Answer 2 Ladder (hard) — Question 2 Why does second ionization energy require more energy than the first ionization energy? Each successive ionization energy requires more energy to remove a valence electron from an atom because after the first ionization energy is supplied (first outer electron removed), there is an increased nuclear pull from the nucleus (due to the presence of a net positive charge with more protons than electrons present). Electron-electron repulsion decreases and electrons are now held more tightly than before. Trying to remove the second electron will require more energy than the first because all the extra energy goes towards overcoming the increased attraction felt between the nucleus and second valence electron. Ladder (hard) — Answer 3 Ladder (hard) — Question 3 Describe the relationship between ionization energy and electronegativity. If it takes more energy to remove an electron (ionization energy) out of an atom, it means that the nucleus has a strong attraction for outer electrons. The atom with a stronger attraction will then attract shared electrons more strongly in whichever bond it is involved with. Therefore, both properties show a positive correlation (as one increases, so does the other). Ladder (hard) — Answer 4 Ladder (hard) — Question 4 What is the periodic trend for ionic size across a period and why? Snakes and Ladders – Page 7 As you move from left to right for the metal side, effective nuclear charge increases because there are more protons than electrons. Thus, the valence electrons feel a stronger pull towards the nucleus causing the valence electrons to move closer to the nucleus, decreasing the ionic size. However, ionic size increases as you move from left to right for nonmetals because they tend to gain electrons which will cause the electron-electron repulsion to increase, making ionic size bigger. www.stao.ca Ladder (hard) — Answer 5 Ladder (hard) — Question 5 Why do noble gases have zero electron affinity? Since noble gases have completely filled stable valence shells, they do not want to gain electrons. Forcing noble gases to accept an extra electron will cause an unstable state for the atom. Ladder (hard) — Answer 6 Ladder (hard) — Question 6 Why does ionization energy decrease as you go down a group? As you go down a group, a shell is added each time, and this successively places valence electrons further away from the nucleus. The valence electrons feel less attraction for the nucleus and therefore, can be easily removed, requiring less IE. Ladder (hard) — Answer 7 Ladder (hard) — Question 7 How are ionization energy and electron affinity similar? The trends involve absorbing and releasing of energies when a valence electron is removed or added to an atom, respectively. Ladder (hard) — Question 8 Ladder (hard) — Answer 8 What are the three factors that affect atom radius? The number of protons, number of energy levels and the shielding effect. Snakes and Ladders – Page 8 www.stao.ca Ladder (hard) — Answer 9 Which is smaller, Na + or Na and why? Na + is smaller because it has acquired a net positive charge which increases the attraction between the nucleus and the valence electrons (increase in ENC) while the shielding effect stays constant causing the ionic radius to be smaller than atomic radius. Ladder (hard) — Question 10 Ladder (hard) — Answer 10 What does Coulomb's law say about attraction between opposite charges? Electrostatic force of attraction between opposite charges decreases as the distance between them increases. Ladder (hard) — Question 9 Ladder (hard) — Answer 11 Ladder (hard) — Question 11 What is the electron shielding effect? Protons inside the nucleus attract the valence electrons. Inner core electrons weaken this attraction between the nucleus and the valence electrons. This effect is known as the electron shielding effect. Ladder (hard) — Answer 12 Ladder (hard) — Question 12 Why does electron shielding not change when going across a period? Snakes and Ladders – Page 9 Electron shielding does not change when going across a period because the number of energy levels does not change, only the number of valence electrons changes. Therefore, there is no increase or decrease in the number of inner core or kernel electrons, so electron shielding remains the same throughout the period. www.stao.ca Ladder (hard) — Answer 13 Describe and explain the general trend for electronegativity across a period. Electronegativity of the atom increases from left to right. This is due to the effective nuclear charge increasing as you go across a period while electron shielding remains the same. Therefore the attraction between the valence electrons and the nucleus becomes stronger across a period, causing atomic size to decrease. As atomic size decreases, stronger attraction is felt between the nucleus and shared electrons in a chemical bond as its outermost shell is closer to the positively charged nucleus. Ladder (hard) — Question 14 Ladder (hard) — Answer 14 Create an equation that incorporates the first ionization energy. X (g) + energy → X + + e - Ladder (hard) — Question 13 Ladder (hard) — Answer 15 Ladder (hard) — Question 15 What is the difference between cations and anions? Cations are formed when an atom loses its valence electron(s) whereas anions are formed when an atom gains valence electron(s). Ladder (hard) — Question 16 Ladder (hard) — Answer 16 Order the following from smallest to largest atomic radius: Fe, Ni, S, Ca, Li. Li Snakes and Ladders – Page 10 < S < Ni < Fe < Ca www.stao.ca Ladder (hard) — Question 17 Ladder (hard) — Answer 17 Create an equation that incorporates electron affinity. X (g) + e - → X - (g) + energy Ladder (hard) — Answer 18 Ladder (hard) — Question 18 What type of element will want to attract electrons and why? Non-metals generally attract electrons easier than metals as they seek to gain valence electrons in order to become isoelectronic with the closest noble gas. Non-metals generally have higher electron affinity and electronegativity values than metals do. Therefore they have an easier ability to gain or attract shared electrons. Ladder (hard) — Answer 19 Give two reasons why potassium is bigger than magnesium. Potassium is below magnesium on the periodic table and therefore has more electron energy levels and more inner core electrons, resulting in a greater electron shielding effect. Another reason why potassium is larger is because magnesium is placed further to the right on its period, giving it a larger ENC value. With an increased effective nuclear charge, the valence electrons in magnesium are more strongly attracted to the nucleus. Therefore it has a smaller atomic radius than potassium Ladder (hard) — Question 20 Ladder (hard) — Answer 20 Why does fluorine have the highest electronegativity and not helium, according to electronegativity trends? All noble gases have an electronegativity of zero because they have a full set of valence electrons therefore they do not seek to share electrons with another atom. Ladder (hard) — Question 19 Snakes and Ladders – Page 11 www.stao.ca Regular (medium) — Question 1 Regular (medium) — Question 1 What group of elements primarily has an electron affinity of zero? The noble gases group has an electron affinity of zero. Regular (medium) — Question 2 Regular (medium) — Question 2 Fill in the blank: The more energy released as a gaseous atom accepts an electron, the ____________ its affinity for an electron will be. The more energy released as a gaseous atom accepts an electron, the higher its affinity for an electron will be. Regular (medium) — Question 3 Regular (medium) — Question 3 Define Effective Nuclear Charge. The apparent nuclear charge, as experienced by the outermost electrons of an atom, as a result of the shielding by the inner-shell electrons. Regular (medium) — Question 4 Regular (medium) — Question 4 Fill in the blank: Increased electron shielding results in ____________ attraction for shared electrons by the nucleus. Increased electron shielding results in less attraction for shared electrons by the nucleus. Snakes and Ladders – Page 12 www.stao.ca Regular (medium) — Question 5 Regular (medium) — Question 5 Define electronegativity. Electronegativity is the measure of the attraction felt by a nucleus of a bonded atom for shared electrons in a chemical bond. Regular (medium) — Question 6 Regular (medium) — Question 6 What are three factors that help explain the trends in the periodic table? Number of protons in the nucleus, number of energy levels, the shielding effect. Regular (medium) — Question 7 Regular (medium) — Question 7 Define ionization energy. The amount of energy required to remove the outermost electron from an atom or ion in the gaseous state. Regular (medium) — Question 8 Regular (medium) — Question 8 Define electron affinity. The energy typically released when an electron is added to a neutral gaseous atom. Snakes and Ladders – Page 13 www.stao.ca Regular (medium) — Question 9 Regular (medium) — Question 9 Why is atomic size hard to measure? It has no definite boundary. Regular (medium) — Question 10 Regular (medium) — Question 10 Fill in the blank: Electron affinity and electronegativity ____________ when going from left to right, across a period. Electron affinity and electronegativity increase when going from left to right across a period. Regular (medium) — Question 11 Regular (medium) — Question 11 Which ion has the smaller ionic radius? K + or Cs + K+ Regular (medium) — Question 12 Regular (medium) — Question 12 Which ion, Al 3+ or P 3- , has the smaller Al 3+ ionic radius? Snakes and Ladders – Page 14 www.stao.ca Regular (medium) — Question 13 Regular (medium) — Question 13 Which atom, Br or F, has the highest electronegativity? F because it is above Br in the group. Regular (medium) — Question 14 Regular (medium) — Question 14 Which atom has the highest first ionization energy: Se , S or Te? S because it is above Se and Te in the group. Regular (medium) — Question 15 Regular (medium) — Question 15 Magnesium has a larger atomic radius than sodium and beryllium. True or False? False. Magnesium is smaller than sodium but bigger than beryllium. Regular (medium) — Question 16 Regular (medium) — Question 16 Helium has the greatest ionization energy and francium has the lowest ionization energy. True or False? True. Ionization energy increases across a period and decreases down a group. Snakes and Ladders – Page 15 www.stao.ca Regular (medium) — Question 17 Regular (medium) — Question 17 Sulfur has a much lower electron affinity than calcium. True or False? False. Electron affinity increases across a period and decreases down a group. Therefore, sulfur has a higher electron affinity than calcium. Regular (medium) — Question 18 Regular (medium) — Question 18 Which is most metallic? K, Rb, or Cs? Cs Regular (medium) — Question 19 Regular (medium) — Question 19 How is effective nuclear charge calculated? nuclear charge + inner core charge Regular (medium) — Question 20 Elements with three energy levels experience a weaker shielding effect than elements with five energy levels do. True or False? Regular (medium) — Question 20 Snakes and Ladders – Page 16 False. Elements with five energy levels are bigger than elements with three energy levels because they have more inner core electrons that increase the shielding effect.