Question

Can you place the following elements in order of decreasing atomic size: selenium, chlorine, fluorine, rubidium, calcium, and sulfur.

Answer 1

The order of decreasing atomic size of the given elements is $\boxed{{\text{Rubidium}}>{\text{Calcium}}>{\text{Selenium}}>{\text{Sulfur}}>{\text{Chlorine}}>{\text{Fluorine}}}$

Further explanation:

Atomic size:

It is defined as the distance between the nucleus and the valence shell where the electrons are located. It has no definite boundary and therefore is difficult to measure.

Atomic size trends in the periodic table:

Along the period, the atomic size decreases as the effective nuclear charge increases from left to right.

Down the group, there is an increase in the number of shells and therefore atomic size increases as we move top to bottom in a group.

Rubidium is a member of alkali metal family and it lies to the leftmost region of the periodic table. So its atomic size is the largest among the given elements.

Calcium is a member of alkaline earth metal family and it lies to the right of rubidium but to the left of the remaining elements. So its atomic size is smaller than that of rubidium but larger than the rest of the elements.

Sulfur and selenium are present in the same group of the periodic table but to the right of both calcium and rubidium. So their sizes are smaller than calcium and rubidium. Selenium lies below sulfur so it will have more atomic size than that of sulfur. So the atomic size of selenium is greater than that of sulfur.

Fluorine and chlorine are present in the same group of the periodic table but to the right of the remaining elements. So their sizes are the smallest among the given elements. Chlorine lies below fluorine so it will have a larger atomic size than that of fluorine. So the atomic size of chlorine is greater than that of fluorine.

So the order of decreasing atomic size of the given elements is as follows:

${\text{Rubidium}}>{\text{Calcium}}>{\text{Selenium}}>{\text{Sulfur}}>{\text{Chlorine}}>{\text{Fluorine}}$

Learn more:

1. Which ion was formed by providing the second ionization energy? brainly.com/question/1398705

2. Write a chemical equation representing the first ionization energy for lithium: brainly.com/question/5880605

Answer details:

Grade: High School

Subject: Chemistry

Chapter: Periodic classification of elements

Keywords: atomic size, fluorine, chlorine, rubidium, calcium, group, period, shells, decreasing atomic size, along the period and down the group.

Answer 2

In periodic table, size increases from top to bottom and will decrease from  left to right.
So the order will be : 
- Rubidium
- Calcium
- Selenium
- Sulfur
- Chlorine
- fluorine

hope this helps