HN HW: Periodic Trends
Master periodic trends! Atomic radius, electronegativity & more. High school chemistry practice.
1. Describe the two factors that explain the periodic trends (across a period and down a group). 2. Match the following: Shielding Effect The decrease of attraction between the nucleus and electrons because of the presence of energy shells Atomic Radius The measure of the distance between radii of two identical atoms of an element Ionization Energy Energy required to remove an electron from an atom Electronegativity The measure of attraction an atom has for electrons in a chemical bond Electron Affinity The energy released by when an atom gains an electron 3. Place the following elements in order of increasing (smallest to largest) atomic radius: B, Ne, Li, N Li, B, N, Ne Ne, N, B, Li 4. Explain why atomic radius increases down a group but decreases across a period. 5. Which element on the periodic table has the largest atomic radius? Fr H He Rn 6. Given the representation of a chlorine atom, which circle might represent an atom of fluorine? Circle B Circle C Circle D 7. Place the following atoms in order of increasing radius: Li+, Be2+, He. Provide an explanation of why you placed them in that order. 8. Explain this trend: Fe > Fe2+ > Fe3+ 9. Place the following elements in order of decreasing (largest to smallest) electronegativity: Br, Cl, I, F F>Cl>Br>I 10. Place the following elements in order of increasing (smallest to largest) ionization energy: B, N, Li, F Li<B<N<F 11. Which element on the periodic table has the largest electronegativity? H He F Fr 12. Why do noble gases not have an electronegativity value? 13. The following table shows the electronegativity values for the halogens. State what kind of pattern exists. 14. Which element has the lower ionization energy, rubidium or iodine? rubidium iodine 15. Compare the shielding effects of boron and gallium. Boron has a larger shielding effect than gallium. Gallium has a larger shielding effect than boron. Gallium and boron have the same shielding effect. 16. Why is the shielding effect the same for magnesium and phosphorus? 17a. Predict the trend in reactivity of the alkali metals as you move down the group. Reactivity increases as you move down the group. Reactivity decreases as you move down the group. 17b. Explain this trend based on one of the periodic trends we discussed (ionization energy, electronegativity, or atomic radius). 18. Ionization Energy The ionization energy is the amount of energy needed to remove an electron from an atom. Which do you think takes more energy, removing an electron from an atom where the nucleus has a tight hold on its electrons, or a weak hold on its electrons? Explain. 19. Ionization Energy Atoms with loosely held electrons are usually classified as metals. They will exhibit high conductivity, ductility, and malleability because of their atomic structure. Would you expect metals to have high ionization energies or low ionization energies? Explain your answer in one to two complete sentences. (Think about how you answered question #18.) 20. Which trend(s) does the following diagram represent? (Multiple Answer, check all that apply) atomic radius ionization energy metal reactivity shielding electron affinity electronegativity 21. Which trend(s) does the following diagram represent? (Multiple Answer, check all that apply) atomic radius ionization energy electronegativity shielding metal reactivity nonmetal reactivity