Warmup

1. Warmup Review the standards below by considering what you have learned on each topic. Identify areas of concern for further review.

2. OCTOBER 6TH, 2010 Review

3. How many neutrons does Potassium usually have? • 15 • 30.974 • 19 • 39.098 • 20 • None of the above

4. What is the atomic mass for an element which has 10 protons and either 10 (60%) or 11 (40%) neutrons? • 10.4 • 20 • 20.4 • 21 • 31

5. What is a possible set of isotopes for an element with an atomic mass of 120.42? • 119 (80%) and 125 (20%) • 120.42 (100%) • 120 (58%) and 121 (42%) • 120 (40%), 121 (37%) and 122 (23%) • None of the above

6. Notetaking Preview

7. Periodic Table Structure 2 10 wide 6 14

8. Orbital Shapes There are 4 types of orbitals: S – comes in sets of 1 – holds 2 electrons P – comes in sets of 3 – holds 6 electrons D – comes in sets of 5 – holds 10 electrons F – comes in sets of 7 – holds 14 electrons Notice that they come in increasingly large odd sets, and this leads to increasingly even numbers of electrons stored there.

9. Pauli’s Exclusion Principle Each orbital can only hold two electrons. One spins one way, the other spins the opposite direction. A Helium atom has one full orbital. How many electrons does it have? A Scandium atom has 10 full orbitals and one half-full orbital. How many electrons does it have? A mystery atom has one full and three half-full orbitalsin its outside layer. How many electrons is that?

10. Aufbau Principle (Filling Order) Electron orbitals are filled in order of the potential energy contained, from least to greatest. Analogy: Football players pile up near the grass. The stack gets higher as more jump on top. To undo the pile, you have to get the top ones off first. You can’t have the football players make a tackle in the air and then add more beneath that! You also can’t get the guy off the bottom before the other people have moved first.

11. Electron Mapping Strategies Count up and follow the shape of the periodic table to get your s’s, p’s, d’s, and f’s in the right order. 1,2 3,4 5-10 11,12 13-18 19,20 21-30 31-36 etc s s p s p s d p Then use the Aufbau diagram to assign numbers. If the number is the same for two in a row, it doesn’t need to be rewritten 1s 2s p 3s p 4s 3d 4p Then use superscripts (looks like exponents) to indicate how many electrons are in each set of orbitals. 1s2 2s2 p6 3s2 p6 4s2 3d10 4p1

12. Periods and Groups Columns are called groups, and groups have similar chemical features. Each group is named. Rows are called periods. Each period represents a new shell which is a set of electron orbitals. Upper periods are inner shells, while the bottom period is the outer shell called the valence shell.

13. Hund’s Rule Nature seeks ‘stable’ arrangements which have the lowest energy. These are: • Whole valence, empty or full • Whole valence, half full • Subset full, rest empty

14. Inner orbitals are filled before outer ones, and simple orbitals are filled before complicated ones. Which idea is this? • Pauli’s Exclusion Principle • Aufbau Principle • Hund’s Rule • Bohr’s Quantization • None of the above

15. A shell with four orbitals (an s and three p’s) can hold eight electrons. This is an example of: • Pauli’s Exclusion Principle • Aufbau Principle • Hund’s Rule • Bohr’s Quantization • None of the above

16. According to Hund’s Rule, what number of electrons might Fluorine give or take in order to become the most stable? • Give 2 • Take 1 • Take 2 • Give 7 • Give 5

17. According to Hund’s Rule, what number of electrons might Magnesium give or take in order to become the most stable? • Take 3 • None, already stable • Take 5 • Give 2 • Give 1

18. According to Hund’s Rule, if there are five electrons in the outer valence, they will be arranged: • 2 in s, 2 in p1, 1 in p2, 0 in p3 • 0 in s, 2 in p1, 2 in p2, 1 in p3 • 1 in s, 2 in p1, 0 in p2, 2 in p3 • 2 in s, 1 in p1, 1 in p2, 1 in p3 • None of the above

19. The correct electron mapping for Aluminum is: • 1s2 2s2 p6 3s2 p6 • 1s2 2s23p6 4s2 p1 • 1s p 2s p 3s2 • 1s2 2s2 p63s2 p1 • None of the above

20. The correct electron mapping for Titanium is: • 1s2 2s2 p6 3s p6 4s2 3d2 • 1s2 2s2 p63s2p6 4s2d2 • 1s2 2s2 p6 3s p6 4s23d10 • 1s2 2s23p6 4s2p6 s • None of the above

21. The correct electron mapping for Sodium is: • 1s2 2s2 3p6 4s1 • 1s2 p6 2s2p63s1 • 1s2 p6 2s2 3p6 4s1 • 1s2 2s2p6 3s1 • None of the above

22. The atom represented by the diagram is which element? • Berylium (Be) • Carbon (C) • Nitrogen (N) • Helium (He) • Phosphorous (P)

23. The atom represented by the diagram is which element? • Berylium (Be) • Aluminum (Al) • Carbon (C) • Oxygen (O) • Phosphorous (P)

24. The atom represented by the diagram is which element? • Berylium (Be) • Lithium (Li) • Oxygen (O) • Aluminum (Al) • None of the above

25. Half-Life and Decay • α (Alpha) – 2 n0 and 2 p+ leave • β (Beta) – 1 n0 turns into a p+ and e- • γ(Gamma) – electromagnetic radiation Now = Then * ½ ^ (t / λ)

26. An element has a half-life of 1 million years. How long will it take for 1000. g of this element to decay down to 7.813 grams? • 1M years • 2M years • 3M years • 4M years • 5M years • 6M years • 7M years • 8M years

27. An alien ring portal thingy was put on Earth 2700 years ago, and was made of 500. kg of radioactive metal. Scientists measure the half-life of a sample and find it to be 900 years. How much metal is left now? • 250 kg • 125 kg • 62.5 kg • 31.3 kg • 15.6 kg • 7.8 kg