TRENDS IN THE PERIODIC TABLE

OBJECTIVES: as given
MTERIAL/APPARATUS: as given
PROCEDURE:
Part One: Atomic Radii of Elements
Graph of Atomic Radii of the First 20 Elements on the Periodic Table

Graph of Ionization Energies of the First 20 Elements from the Periodic Table

QUESTIONS/DISSCUSSIONS
Part One:
1. What is the group name for the elements found at the peals of your graph? What is the group located on the periodic table.
The group name of the elements at the peaks is Alkali Metals. The group is located at the most left column on the periodic table.

2. What is the group name for the elements found at the troughs of your graph? Where is this group located on the Periodic table?
The group name of the elements at the troughs is Noble Gases. The group can be found at the very right column on the periodic table.

3. What is the trend in the size of atomic radii as the atomic number increases within a group?
The atomic radii increase as the atomic number increases within a group.

4. What is the trend in the size of atomic radii as the atomic number increases across a period or row?
The atomic radii decrease through each period from left to right.

5. Estimate the atomic radius for Cesium, using graphical method or any other.
The slope of the secant line can be determined as the rate of change in atomic radii of the elements in Alkali Metals in each period. mT= == 40 y-y1= mT (x-x1) y-155= 40(x-2) y=40x + 75 when x=6(Alkali Metals, group period 6, Cesium), y= 315 Therefore the predicted atomic radii of Cesium would be 315 pm.

Part Two:
1. What group of elements corresponds to the peaks of ionization energy on your graph? Where is this group located on the Periodic Table? Is it the same group that had the highest atomic in Part One.
The group name of the elements at the troughs is Noble Gases. The group can be found at the very left column on the periodic table. it is not the same group that has the highest atomic radii in Part One, instead, it has the lowest atomic radii among all the groups.

2. Which group of elements occupies the troughs on your graph of ionization energy? Suggest a reason for this?
The elements occupies the troughs are the ones in the group