Trends in atomic size: opposite of trend in ionization energy

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Presentation transcript:

Trends in atomic size: opposite of trend in ionization energy QUESTION: Which of the following has the smallest atomic radius? A. O, B. S, C. Li Trends in atomic size: opposite of trend in ionization energy Across a given period among representative elements (A groups): decreasing Going up a group: decreasing SCRIPT: Which of the following has the smallest atomic radius? A. O, B. S, C. Li PAUSE CLICK The trend in atomic size is opposite that of the trend in ionization energy. The observed general trend is that it decreases as you from go from left-to-right across any given period. A period refers to a horizontal row in the periodic table. The trend is also decreasing as you go up a group. A group refers to a vertical column in the periodic table. So… let’s locate these elements in the periodic table Here’s lithium CLICK Here’s sulfur CLICK and here’s oxygen You’ll note that sulfur and oxygen are in the same group --- group six A. The trend going up a group is decreasing. Therefore oxygen is smaller than sulfur. As for lithium, it’s in the same period as oxygen --- period 2. The trend across a period, from left to right, … is decreasing. Therefore, oxygen is smaller than lithium. Since oxygen is smaller than either lithium or sulfur. The correct answer is A. Of the three choices given, oxygen is the smallest. END RECORDING

decreasing decreasing

QUESTION: Which of the following has the smallest atomic radius? A. O, B. S, C. Li SCRIPT: Which of the following has the smallest atomic radius? A. O, B. S, C. Li PAUSE CLICK The trend in atomic size is opposite that of the trend in ionization energy. The observed general trend is that it decreases as you from go from left-to-right across any given period. A period refers to a horizontal row in the periodic table. The trend is also decreasing as you go up a group. A group refers to a vertical column in the periodic table. So… let’s locate these elements in the periodic table Here’s lithium CLICK Here’s sulfur CLICK and here’s oxygen You’ll note that sulfur and oxygen are in the same group --- group six A. The trend going up a group is decreasing. Therefore oxygen is smaller than sulfur. As for lithium, it’s in the same period as oxygen --- period 2. The trend across a period, from left to right, … is decreasing. Therefore, oxygen is smaller than lithium. Since oxygen is smaller than either lithium or sulfur. The correct answer is A. Of the three choices given, oxygen is the smallest. END RECORDING

Video ID: 2-6-4 © 2008, Project VALUE (Video Assessment Library for Undergraduate Education), Department of Physical Sciences Nicholls State University Author: Glenn V. Lo Narrator: Funded by Louisiana Board of Regents Contract No. LA-DL-SELECT-13-07/08