MAIN GROUP (GROUPS 1, 2, AND 13 - 18) ELEMENTS NOTES

## ION (smaller or larger) THAN ATOM

1

2

13

14

15

16

17

18

LOCATING MAIN GROUP ELEMENTS ON THE PERIODIC TABLE NOTES

Given the electron configuration or noble gas configuration for an element, it is possible to determine its location on the Periodic Table without actually looking at a Periodic Table.

* To tell which period this element is in...

~  find the highest occupied energy level for this element

You can do this by...

~  finding the largest coefficient number

The largest coefficient number is the number of the period where the element is located.

* To tell which "block" this element is in...  (like "s" block, "p" block, "d" block, etc)

~  find the highest occupied sublevel for this element

You can do this by...

~  finding the last lowercase letter written

The last lowercase letter written in the configuration is the "block" where the element is located.

* To tell which group this element is in...

~  find the highest occupied energy level for this element

You can do this by...

~  finding the largest coefficient number

Then...

~  add up the exponents of the largest coefficient number

This gives you the number of valence electrons in the element.

You will then know that 1 valence e- indicates that the element is in Group 1, 2 valence e- indicates that the element is in Group 2, 3 valence e- indicates that the element is in Group 13, 4 valence e- indicates that the element is in Group 14, 5 valence e- indicates that the element is in Group 15, 6 valence e- indicates that the element is in Group 16, 7 valence e- indicates that the element is in Group 17, and 8 valence e- indicates that the element is in Group 18.

Look at the following example:

EXAMPLE:                [Ar] 4s2 3d10 4p5

It is possible to tell the period, group, and "block" where this element is located.

*  Period --  largest coefficient number is 4, so element is in Period 4

*  Block--  last lowercase letter written is "p", so element is in "p" block

*  Group--  largest coefficient number is 4...  2 electrons in 4s, 5 electrons in 4p -->  total of 7 valence electrons,

so this element is in Group 17.

LOCATION OF ELEMENTS WORKSHEET

 Noble Gas Config. Period Block (s, p, d, f) Group 1 [Ne] 3s2 3p2 2 [Ar] 4s2 3d10 4p6 3 [Xe] 6s2 4 [Kr] 5s2 4d10 5p5 5 [Ar] 4s2 3d10 4p1 6 [He] 2s2 2p3 7 [Kr] 5s2 4d10 5p4 8 [He] 2s1 9 [Xe] 6s2 4f14 5d10 6p2 10 [Rn] 7s2

HISTORY OF THE PERIODIC TABLE NOTES

I.  Mendeleev and Chemical Periodicity

A.  Wanted to organize elements according to their ____________________

B.  When elements were arranged in order of increasing atomic mass*, similarities in chemical

properties appeared at regular intervals (____________________)

C.  *Several elements did not quite fit this pattern - Mendeleev put elements with similar

____________________ in the same column or group

D.  1871 - Mendeleev predicted the existence and properties of several (then undiscovered)

elements.  These elements were:

E.  Within 15 years, those elements with those properties had been discovered

II.  Moseley and the Periodic Law

A.  When elements were arranged in order of increasing ___________________________________,

there was a distinct regular pattern.

B.  ____________________:  The physical and chemical properties of the elements are periodic

functions of their atomic numbers.

C.  In other words, when elements are arranged in order of increasing atomic number, elements

with similar properties appear at regular intervals.

D.  Bottom line = elements in the same group have similar properties

III.  Modern Periodic Table:  arrangement of the elements in order of their atomic numbers so that elements with

similar properties fall in the same group

ELECTRON CONFIGURATION & THE PERIODIC TABLE NOTES
I.
Stability of Noble Gases

A.  Noble gases undergo very few chemical reactions - why?

B.  Highest occupied energy level contains ________________________________________

C.  Electrons in the highest occupied energy level are what determines an element's _____________

II.  Periods and Blocks of the Periodic Table

A.  Horizontal row = ____________________;  7 on modern Periodic Table

B.  Length of period determined by the sublevels being filled in that period

C.  Period 1:  only _____ sublevel being filled;  can hold a maximum of _____ electrons;

period contains _____ elements

D.  Period 4:  ____, ____, and ____ sublevels being filled;  s can hold ___ electrons, d can hold ___

electrons, & p can hold ___ electrons; total of _____ electrons;

Period 4 contains _____ elements

E.  Period can be determined from the element's electron configuration

1.  Bromine:  [Ar] 4s2 3d10 4p5

2.  Highest number in front of letter is the element's highest occupied _____________________ -

tells which period the element is in

3.  For bromine, _____ is highest number, so it is in Period _____
III.  The "s" block elements:  Groups 1 and 2

A.  Group 1 - Alkali Metals

1.  generalized outermost energy level (valence) electron configuration:

2.  silvery appearance

3.  soft enough to cut with a knife

4.  not found in nature as free elements - they're always part of a compound

B.  Group 2 - Alkaline Earth Metals

1.  generalized valence electron configuration:

2.  harder, stronger, more dense than Group 1

3.  also have higher melting points than Group 1

4.  less reactive than Group 1, but still not found in nature as free elements

C.  Exceptions:  Hydrogen and Helium

1.  Hydrogen (H)

a.  electron configuration:

b.  properties do not resemble those of any other element on the periodic table

2.  Helium (He)

a.  electron configuration:

b.  in Group 18 because
IV.  The "d" block elements: Groups 3 - 12

A.  called

B.  have typical metallic properties:  ductile, malleable, shiny, solid, conduct electricity

C.  less reactive than "s" block elements

D.  found in nature as free elements

E.  usual ending of electron configuration:
V.  The "p" block elements:  Groups 13 - 18

A.  "s" and "p" block elements together referred to as _____________________________ elements

B.  ending electron configurations of __________________ through ___________________

C.  properties vary greatly b/c there are metals, metalloids, and nonmetals

D.  Group 17 - Halogens

1.  most reactive nonmetals

2.  seven electrons in outermost energy level

E.  "p" block metals are harder and more dense than "s" block , but not as hard or dense as the "d"

block metals

PERIODIC TRENDS NOTES

Electronegativity/Electron Affinity (EN/EA):  measure of how much an atom wants to gain an electron

EN/EA Left to Right across a Period:                INCREASES  (not including Noble Gases)

Why?

* Elements on the left side of the P.T. (metals) want to lose electrons.  Elements on the right side of the P.T.

(nonmetals) want to gain electrons.  Trend does not include Noble Gases because these elements do not want to

lose or gain electrons.

EN/EA Top to Bottom in a Group:                   DECREASES

Why?

*

This interference (and resulting decreased hold) is referred to as the SHIELDING EFFECT.

Ionization Energy (IE):  amount of energy required to remove an atoms most loosely held electron

IE Left to Right across a Period:            INCREASES

Why?

* Elements on the left side of the P.T. (metals) want to lose electrons.  Therefore, it will not require

much energy to remove an electron.  Elements on the right side of the P.T. (nonmetals) want to gain

electrons.  Consequently, a lot of energy will be needed to remove (take away) an electron.

IE Top to Bottom in a Group:                DECREASES

Why?

*

Atomic Radius (AR):  distance from the nucleus to the H.O.E.L.

AR Left to Right across a Period: DECREASES

Why?

*

AR Top to Bottom in a Group:     INCREASES

Why?

* There are more occupied energy levels as you move towards the bottom of the P.T.

Metallic Character:  how easily an atom will lose valence electrons (easier to lose = more metallic = more reactive METAL)

Which metal loses its valence electron(s) most easily? Fr

Why?

* Francium has one valence electron.  It is more reactive than elements at the top of Group 1 because there are many inner shell electrons that decrease the attraction the nucleus has for the valence electrons.

Nonmetallic Character:  how easily an atom will gain electrons (easier to gain = more nonmetallic = more reactive NONMETAL)

Which nonmetal gains electron(s) most easily?           F

Why?

* Fluorine has seven valence electrons.  It is more reactive than elements at the bottom of Group 17 because there are only a few inner shell electrons.  Consequently, the nucleus has a strong attraction for other electrons.

PERIODIC TRENDS (multiple choice w/o using Periodic Table) WORKSHEET
1.)  Which element is most metallic?

(A) Group 14, Period 2                  (B) Group 14, Period 3

(C) Group 14, Period 4                  (D) Group 14, Period 5

2.)  Which element is most nonmetallic?

(A) Group 16, Period 2                  (B) Group 16, Period 3

(C) Group 16, Period 4                  (D) Group 16, Period 5

3.)  Which has the largest atomic radius?

(A) Group 1, Period 2                   (B) Group 13, Period 2

(C) Group 15, Period 2                  (D) Group 17, Period 2

4.)  Which has the highest ionization energy?

(A) Group 2, Period 3                   (B) Group 2, Period 4

(C) Group 2, Period 5                   (D) Group 2, Period 6

5.)  Which has the most metallic properties?

(A) Group 13, Period 5                  (B) Group 14, Period 5

(C) Group 15, Period 5                  (D) Group 16, Period 5

6.)  Which has the greatest electron affinity?

(A) Group 16, Period 4                  (B) Group 16, Period 5

(C) Group 17, Period 5                  (D) Group 17, Period 4

7.)  Which has the smallest atomic radius?

(A) Group 15, Period 2                  (B) Group 15, Period 3

(C) Group 15, Period 4                  (D) Group 15, Period 5

8.)  Which has the lowest electron affinity?

(A) Group 13, Period 3                  (B) Group 15, Period 3

(C) Group 17, Period 3                  (D) Group 18, Period 3

9.)  Which has the lowest ionization energy?

(A) Group 1, Period 2                   (B) Group 1, Period 3

(C) Group 1, Period 4                   (D) Group 1, Period 5

10.)  Which has the most metallic properties?

(A) Group 15, Period 5                  (B) Group 16, Period 5

(C) Group 15, Period 6                  (D) Group 16, Period 6

11.)  Which would most easily lose its valence electrons?

(A) Group 1, Period 3                   (B) Group 14, Period 2

(C) Group 17, Period 3                  (D) Group 18, Period 2

12.)  Which would most easily gain electrons?

(A) Group 13, Period 3                  (B) Group 14, Period 2

(C) Group 15, Period 2                  (D) Group 17, Period 3

13.)  Which has an octet of electrons in its outermost energy level?

(A) Group 13, Period 3                  (B) Group 14, Period 2

(C) Group 18, Period 2                  (D) Group 17 , Period 5

14.)  Which has chemical properties most similar to [Ar] 4s1?

(A) Group 1, Period 3                   (B) Group 2, Period 3

(C) Group 13, Period 3                  (D) Group 14, Period 3

15.)  Which is most reactive?

(A) Group 14, Period 2                  (B) Group 17, Period 2

(C) Group 15, Period 2                  (D) Group 18, Period 2

16.)  Which is most reactive?

(A) Group 13, Period 2                  (B) Group 1, Period 5

(C) Group 2, Period 5                   (D) Group 13, Period 5

17.)  Which has chemical properties most similar to [Ne] 3s2 3p5?

(A) Group 16, Period 3                  (B) Group 18, Period 3

(C) Group 17, Period 4                  (D) Group 18, Period 2

18.)  Which would never be found in the free state?

(A) Group 1, Period 4                   (B) Group 13, Period 3

(C) Group 15, Period 3      (D) Group 14, Period 4

19.)  Which is the least reactive gas?

(A) Group 16, Period 2                  (B) Group 15, Period 2

(C) Group 17, Period 2                  (D) Group 18, Period 2

20.)  Which is the most reactive gas?

(A) Group 16, Period 2                  (B) Group 15, Period 2

(C) Group 17, Period 2                  (D) Group 18, Period 2

21.)  Which would never be in a compound?

(A) Group 1, Period 1                   (B) Group 18, Period 1

(C) Group 13, Period 2                  (D) Group 1, Period 2

22.)  Which would be found in the d block of elements?

(A) Group 1, Period 3                   (B) Group 11, Period 4

(C) Group 17, Period 5                  (D) Group 14, Period 2

1.) Color the s block area pink.

2.) Color the p block area yellow.

3.) Color the d block area light green.

4.) Color the f block area orange.

5.) Draw an X in the boxes that represent the unreactive elements

6.) Draw a diagonal line (from upper left to lower right) in the area that represents the very reactive nonmetals.

7.) Draw a diagonal line (from upper right to lower left) in the area that represents the very reactive metals.

8.) Draw a purple capital letter R with a circle around it at the location that represents the element with the largest

atomic radius.

9.) Draw a blue capital letter I with a diamond around it at the location that represents the element with the

highest ionization energy.

10.)  Draw a dark green capital letter E with a triangle around it at the location that represents the element with

the highest electronegativity/electron affinity.

11.) Outline in black the boxes where metalloids with more nonmetallic properties are located.

12.) Outline in red the boxes where metalloids with more metallic properties are located.

13.) Draw a star in the location that represents the most metallic element (or most reactive metal).

14.) Draw a heart in the location that represents the most nonmetallic element (or most reactive nonmetal).

**Doing this correctly will aid you in studying for your Unit 5 test.  This summarizes the bulk of the information covered.  REMINDER:  You will not have a Periodic Table to use during your Unit 5 test.**