Place the following elements in order of decreasing atomic size: selenium, chlorine, fluorine, rubidium, calcium, and sulfur.
To place the elements in order of decreasing atomic size, we need to analyze their position on the periodic table. Atomic size generally decreases as you move from left to right across a period and increases as you move down a group. Let's go step by step:
1. Rubidium (Rb): Rubidium is the largest atom on the list because it is located at the bottom-left of the periodic table in Group 1 (alkali metals). Moving down the group, atomic size increases due to the addition of new electron shells.
2. Calcium (Ca): Calcium is smaller than rubidium but larger than the remaining elements on the list. It is in Group 2 (alkaline earth metals) and follows the general trend of increasing atomic size down a group.
3. Selenium (Se): Selenium is relatively smaller than rubidium and calcium. It is a nonmetal located in Group 16 (chalcogens). Moving from left to right across a period, atomic size generally decreases.
4. Sulfur (S): Sulfur is smaller than selenium but larger than the remaining elements. It is also a nonmetal in Group 16. So, it follows the same trend of decreasing atomic size when moving across a period.
5. Chlorine (Cl): Chlorine is smaller than both selenium and sulfur. It is a nonmetal in Group 17 (halogens), which also follows the trend of decreasing atomic size across a period.
6. Fluorine (F): Fluorine is the smallest atom on the list. It is also a nonmetal in Group 17, and it has the smallest atomic size due to its position at the top-right of the periodic table.
So, the order of decreasing atomic size is: Rubidium (Rb) > Calcium (Ca) > Selenium (Se) > Sulfur (S) > Chlorine (Cl) > Fluorine (F).
To determine the order of decreasing atomic size, we need to understand the periodic trend known as atomic radius. Atomic radius generally decreases across a period (from left to right) and increases down a group (from top to bottom) in the periodic table.
Let's analyze the elements one by one:
1. Fluorine (F) is the first element. It belongs to the halogen family and is located in group 17 of the periodic table. Going from left to right across a period, atomic size decreases. Hence, fluorine will be the smallest atom in this set.
2. Chlorine (Cl) is the second element. It is also a halogen and follows similar trends as fluorine. However, since chlorine is located one period below fluorine, its atomic size is larger than fluorine's.
3. Selenium (Se) is the third element. It is located in group 16, which is one period below halogens and two periods below fluorine. Therefore, its atomic size will be larger than fluorine and chlorine.
4. Sulfur (S) is the fourth element in this set. It follows the same periodic trend as selenium but is located one period above it. Since atomic size decreases across a period, sulfur will have a smaller atomic size than selenium.
5. Calcium (Ca) is the fifth element. It is an alkaline earth metal, located in group 2 of the periodic table. Going from left to right across a period, atomic size decreases. Therefore, calcium will have a smaller atomic size than selenium, sulfur, chlorine, and fluorine.
6. Rubidium (Rb) is the last element. It is an alkali metal located in group 1. Alkali metals have the largest atomic size in their respective periods. Thus, rubidium will have the largest atomic size among the given elements.
Based on the analysis above, the elements arranged in order of decreasing atomic size are:
Rubidium > Selenium > Sulfur > Chlorine > Calcium > Fluorine