Name: ____________________________ Period: _______ Periodic Trends Activity

Use the site Webelements at http://www.webelements.com to answer the following questions:

1. For the first three Alkali Metals (Li, Na and K) determine the atomic radius. At Webelements look under Atom Properties, Atom Sizes, and record the atomic radius (calculated).

Li _______ pm Na _______ pm K _______ pm

In which direction in this group does the atomic radius increase? __________________

Now look up the atomic radius for the first three Alkaline Earth Metals, Chalcogens and Halogens:

Be _______ pm Mg _______ pm Ca _______ pm

O _______ pm S _______ pm Se _______ pm

F _______ pm Cl _______ pm Br _______ pm

In which direction in these groups does the atomic radius increase? __________________

Draw an arrow vertically in the direction that atomic radius tends to increases on the periodic table at the end of this document. Label this arrow (a).

Now look up the atomic radius for the elements in the second and third periods of the Periodic Table. You already have half of these, so just copy them from above.

Period 2:

Li _______ pm Be _______ pm B _______ pm C _______ pm

N _______ pm O _______ pm F _______ pm Ne _______ pm

Period 3:

Na _______ pm Mg _______ pm Al _______ pm Si _______ pm

P _______ pm S _______ pm Cl _______ pm Ar _______ pm

In which direction in these periods does the atomic radius increase? __________________

Draw an arrow horizontally in the direction that atomic radius tends to increases on the periodic table at the end of this document. Label this arrow (a).

2. For the first three Alkali Metals (Li, Na and K) determine the 1^st ionization energy. At Webelements look under Atom Properties, Electron Shell Properties, and record the Enthalpy to the tenths place.

Li _______ kJ/mole Na _______ kJ/mole K _______ kJ/mole

In which direction in this group does the 1^st ionization energy increase? __________________

What is the definition of ionization energy? ________________________________________________

____________________________________________________________________________________

Now look up the 1^st ionization energy for the first three Alkaline Earth Metals, Chalcogens and Halogens:

Be _______ kJ/mole Mg _______ kJ/mole Ca _______ kJ/mole

O _______ kJ/mole S _______ kJ/mole Se _______ kJ/mole

F _______ kJ/mole Cl _______ kJ/mole Br _______ kJ/mole

In which direction in these groups does the 1^st ionization energy increase? __________________

Draw an arrow vertically in the direction that the 1^st ionization energy tends to increases on the periodic table at the end of this document. Label this arrow (b).

Now look up the 1^st ionization energy for the elements in the second and third periods of the Periodic Table. You already have half of these, so just copy them from above.

Period 2:

Li _______ kJ/mole Be _______ kJ/mole B _______ kJ/mole C _______ kJ/mole

N _______ kJ/mole O _______ kJ/mole F _______ kJ/mole Ne _______ kJ/mole

Period 3:

Na _______ kJ/mole Mg _______ kJ/mole Al _______ kJ/mole Si _______ kJ/mole

P _______ kJ/mole S _______ kJ/mole Cl _______ kJ/mole Ar _______ kJ/mole

In which direction in these periods does the 1^st ionization energy increase? __________________

Draw an arrow horizontally in the direction that the 1^st ionization energy tends to increases on the periodic table at the end of this document. Label this arrow (b).

Is this trend partially or completely periodic? _________________________

Using Excel, make a line graph of the atomic number for elements 3-18 with the 1^st ionization energy.

3. For the first three Alkali Metals (Li, Na and K) determine the electronegativity. At Webelements look under Chemistry and Compounds, Electronegativities, and record the Pauling electronegativity to the hundredths place. There are no units other than saying “Pauling units”.

Li _______ Na _______ K _______

In which direction in this group does the electronegativity increase? __________________

What is the definition of electronegativity? ________________________________________________

____________________________________________________________________________________

Now look up the electronegativity for the first three Alkaline Earth Metals, Chalcogens and Halogens:

Be _______ Mg _______ Ca _______

O _______ S _______ Se _______

F _______ Cl _______ Br _______

In which direction in these groups does the electronegativity increase? __________________

Draw an arrow vertically in the direction that electronegativity tends to increases on the periodic table at the end of this document. Label this arrow (c).

Now look up the electronegativity for the elements in the second and third periods of the Periodic Table. You already have half of these, so just copy them from above.

Period 2:

Li _______ Be _______ B _______ C _______

N _______ O _______ F _______ Ne _______

Period 3:

Na _______ Mg _______ Al _______ Si _______

P _______ S _______ Cl _______ Ar _______

In which direction in these periods does the electronegativity increase? __________________

Draw an arrow horizontally in the direction that electronegativity tends to increases on the periodic table at the end of this document. Label this arrow (c).

(a) atomic radius increases

(b) 1^st ionization energy increases

(c) electronegativity increases