Modified Periodic Table
1 1e +1 |
18 8e 0 |
||||||||
1 |
1 1776 Hydrogen 1.008 |
2 2e +2 |
13 3e +3 |
14 4e +/-4 |
15 5e -3 |
16 6e -2 |
17 7e -1 |
2 1868 Helium 4.003 |
|
2 |
3 1817 Lithium 6.941 |
4 1798 Beryllium 9.012 |
|
5 1808 Boron 10.811 |
6 ? Carbon 12.011 |
7 1772 Nitrogen 14.007 |
8 1774 Oxygen 15.999 |
9 1886 Flourine 18.998 |
10 1898 Neon 20.180 |
3 |
11 1807 Sodium 22.990 |
12 1808 Magnesium 24.305 |
|
13 1827 Aluminum 20.982 |
14 1824 Silicon 28.086 |
15 1669 Phosphorus 30.974 |
16 ? Sulfur 32.066 |
17 1774 Chlorine 35.453 |
18 1894 Argon 39.948 |
4 |
19 1807 Potassium 39.098 |
20 1808 Calcium 40.078 |
|
31 1875 Gallium 69.723 |
32 1886 Germanium 72.61 |
33 1250 Arsenic 74.922 |
34 1817 Selenium 78.96 |
35 1826 Bromine 79.904 |
36 1898 Krypton 83.80 |
5 |
37 1860 Rubidium 85.468 |
38 1790 Strontium 87.62 |
|
49 1863 Indium 114.818 |
50 ? Tin 118.710 |
|
|
|
|
| Blocks | Metals | Nonmetals | Metallloids |
| Names | Red- Gas | Blue- Liquid | Black- Solid |
Observe the arrangement of elements. What patterns can you find? |
| The "e" stands for electrons. The first column of elements has 1 valence electron. The second column has 2 valence electrons. Although helium is in the last column, it has only one orbital and 2 valence electrons. Why is helium in the last column instead of the second column? |
| The + and - signs stand for how many electrons the element is willing to give or take. Sodium will give 1 electron. Chlorine will take 1 electron. When these two elements bond, they will each have a full valence of 8 electrons. For simple bonds between atoms think 8 is great, unless it's hydrogen, then 2 will do. There's more to the story, but that will come later. |
Chemical Bonds Metallic Bonds Metallic bonds form when metals bond with metals. In a metallic bond, electrons are shared in "sea of electrons." This explains why metals are such good conductors of electricity. Ionic Bonds In an ionic bond, one atom give an electron to the other. Ionic bonds form between metals and nonmetals. The Alkali Metals and Halogens readily form ionic compounds. Covalent Bonds When atoms share electrons a covalent bond is formed. The valence electrons are move about in the valence of each bonding atom. Sometimes there is an imbalance in the sharing. This creates a polar molecule. The atom that pulls the electrons toward it develops a negative charge. The atom from which the electrons are pulled develops a positive charge. Hyrdrogen Bonds Hydrogen has only one electron. It cannot give up its electron, but will share it. Because hydrogen is so much smaller than any other element except itself, it tends to form polar molecules. TRY THIS: See if you can predict whether the bond will be ionic or covalent. Ionic bonds will show the transfer of electrons from red to blue. Covalent bond will appear as fuzzy color bands. Iowa State University Materials: Modified Periodic Table and Bonding Organizer
|