Write a hypothesis to tell what you think happens to the atomic radius as you move across a period. Use this template to form your answer, "If you move from left to right across a period,then the atomic radius will...because..."
The elements below are all from the same period and have the same number of energy levels. The name of the element is followed by its atomic radius. Put them in order by the Zeff for their valence electrons so that the one with Zeff of 1 is first, then 2, then 3, etc. Remember that elements in column 1 have a Zeff of 1 and elements in column 2 have a Zeff of 2, etc.
Sodium 186 pm
silicon 118 pm
Phosphorus 110 pm
aluminum 143 pm
magnesium 160 pm
sulfur 103 pm
argon 97 pm
chlorine 99 pm
Make a graph that shows Zeff of each element from question 2 on the x axis and atomic radius on the y-axis. Plot the points, connect them, and give the graph a title.
Write a claim to tell what does happen to the atomic radius as you move across a period/row on the periodic table.
Give Evidence from the graph to support your claim.
Reasoning: Explain why the trend works this way. Be sure to discuss the effect of Zeff and electron shielding in your work.