Grab a Marker and Trade Papers POGIL Answer Keys Grab a Marker and Trade Papers

2 / x Average Atomic Mass 12 24, 25, and 26 No, some have more mass that the others Mass 24 – 16 Mass 25 – 2 Mass 26 – 2 5. 24Mg 6. Mass 24 – 8 Mass 25 – 1 Mass 26 – 1

2 / x 7a. Mass 24 – 16 Mass 25 – 2 Mass 26 – 2 7b. It matches the model in Model 1 24 amu – as that has the greatest abundance 9a. 24.306 9b. No 10a. It would be too much to squeeze into one box 10b. As the physical and chemical properties of isotopes are the same it is not usually important to scientists.

2 / x 11. Mary’s method = 24.305 amu Jack’s method = 24.305 amu Alan’s method = 24.984 amu 12a. Mary and Jack 12b. Alan’s method incorrectly weights all the isotopes the same 13. 15.999 amu 14a. 24Mg 14b. As 24Mg is the most abundant the weighted average will be closest to 24Mg 15. As the average mass is 10.81 boron-11 must be most abundant.

2 / x 16a. Yes 16b. No, as the composition is identical 16c. The bonding between the atoms makes the difference. 17. Allotrope – same composition, but different characteristics because of different bonding

2 / x Coulombic Attraction + = proton, - = electron Attraction As distance increases the force of attraction decreases. Less than Greater than 6a. The force of attraction 6b. The strength 7a. It increases 7b. In decreases 8. More protons make for a larger force 9. 11.5 x 10-8 N 10. It should decrease

2 / x 11. Row 12. 13. Chlorine 14a. No 14b. No 14c. Na = 11, Al = 13, Cl = 17 14d. Yes – more protons means more attraction 15a. Ca 15b. Cu 15c. Ar 16a. Li = 3, Na = 11, K = 19 16b. Distance as the force of attraction decreases while also having more protons

2 / x 17a. Inverse 17b. Direct

2 / x Electron Energy and Light Shades of the color Yes Violet = highest 4. red = lowest 5a. Red 5b. Violet 5c. Wavelength is inversely related to frequency 6. There are lines that are different Attract Attraction, stonger Gain Lose

2 / x 11. Absorbed to travel farther from the nucleus 12a. Picture B 12b. Releases 12c. Higher, lower 12d. Released 13.

2 / x 14a. n = 6 to n = 2 14b. The greater change in distance means the greater change in energy. 15. It only has 1 electron 16. Many, many H atoms each with their electrons making different transitions. 17a. n = 7, 6, 5, 4, 3, or 2 to n=1 17b. n = 7, 6, 5, or 4 to n = 3 18a. Li and Na are not present 18b. H and He are present 19. Emission and absorption spectrum would have lines at the same energies (wavelengths) but one is emitted lines (bright lines of color) and one absorbed lines (lines of black within the rainbow)

2 / x Periodic Trends 1a. The first number 1b. pm 1c. The size of the atom (from center of nucleus to valence energy level) 2. Atomic radius increases 3. The atomic radius increases as the number of energy levels increases 4. Atomic radius decreases 5. The effective nuclear charge increases and pulls the electrons closer 6a. It takes energy to pull apart attracted particles 6b. Tight = more energy

2 / x 7. Ionization energy decreases 8. The farther distance between the nucleus and the electrons means less energy needed to remove the electron. 9. Ionization energy increases 10. The greater effective nuclear charge requires more energy to remove electrons 11. Metals should have low ionization energy, so the electrons are easy to move allowing for high conductivity, malleability, and ductillity. 12. Diagram B

2 / x 13a. Electronegativity decreases 13b. The increased distance means the nucleus of one atom is farther from the electrons of the other atom, so it has a weaker attraction. 13c. It increases 13d. The greater effective nuclear charge allows the nucleus to pull with greater attraction. 14. (on the left)= Electronegativity and I.E. (on the right)= atomic radius

2 / x 15a. Skip (IE of O is less than N) 15b. Skip (Oxygen’s last electron is in an orbital already containing an electron, so the increase of electron-electron repulsion between the electrons make it easier to remove, even with more effective nuclear charge) 16. Ba, Fe, Br