Group+2

=**Alkali Earth Metals**=


 * They are metallic elements
 * Found in the second group of the periodic table
 * They are very reactive
 * They are so reactive because of there oxidation number of +2
 * These metals are not found in nature free
 * Trends: Quantum Numbers are the same except for the n quantum number.
 * For more information please visit [] or [].

**Beryllium**

 * Symbol: Be

[[image:http://periodictable.com/Samples/004.1/s9s.JPG width="183" height="183" align="right" caption="http://periodictable.com/Samples/004.1/s9s.JPG"]]
Discovered in 1798 by Fredrich Wohler. Beryllium is used in spacecrafts, missiles, x-rays, gyroscopes, computer parts, and air crafts. It is found in 30 species and it has the highest melting point of the light metals of1278.0 Degrees Celsius.
 * Atomic Number: 4
 * Atomic Mass: 9.012182 amu
 * Number of Protons: 4
 * Number of Electrons: 4
 * Number of Neutrons: 5
 * Isotopes:
 * Be-7: 53.3 Days
 * Be-9: Stable
 * Be-10: 2600000.0 years
 * Crystal Structure: Hexagonal
 * Color: Grey
 * Electron Configuration: 1s2 2s2
 * Quantum Numbers:
 * n= 2
 * l= 0
 * ml= 0
 * ms= -1/2

**Magnesium**
Discovered in 1808 by Sir Humphrey Davy. Obtained from sea water. Uses are are in air planes, missiles, food, and drugs. You can find it in food such as: Spinach, Legumes (beans and peas), nuts, seeds, milk, bran flakes, peanut butter, halibut, potato, rice, chocolate milk, rice, avocado, and unrefined grains.
 * Symbol: Mg[[image:http://periodictable.com/Samples/012.15/s12s.JPG width="185" height="185" align="right" caption="Magnesium Crystal" link="@http://periodictable.com/Samples/012.15/s13.JPG"]]
 * Atomic Number: 12
 * Atomic Mass: 24.305 amu
 * Number of Protons: 12
 * Number of Electrons: 12
 * Number of Neutrons: 12
 * Isotopes:
 * Mg-24, 25, 26: Stable
 * Mg-27: 9.45 minutes
 * Mg-28: 21.0 hours
 * Crystal Structure: Hexagonal
 * Color: Grayish
 * Electron Configuration: 1s2 2s2 2p6 3s2
 * Quantum Numbers:
 * n= 3
 * l= 0
 * ml= 0
 * ms= -1/2

**Calcium**
Discovered in 1808 by Sir Humphrey Davy. It comes from Limestone, Chalk, and Marble. It is used in growth of bones and shells.
 * Symbol: Ca[[image:http://periodictable.com/Samples/020.6/s12s.JPG width="182" height="182" align="right" caption="Calcium Square block" link="@http://periodictable.com/Samples/020.6/s13.JPG"]]
 * Atomic Number: 20
 * Atomic Mass: 40.078 amu
 * Number of Protons: 20
 * Number of Electrons: 20
 * Number of Neutrons: 20
 * Isotopes:
 * Ca-40, 42, 43, 44, 46, 48: Stable
 * Ca-41: 103000.0 years
 * Ca-45: 162.7 days
 * Ca-47: 4.5 days
 * Ca-49: 8.7 minutes
 * Crystal Structure: Cubic
 * Color: Silvery
 * Electron Configuration: 1s2 2s2 2p6 3s2 3p6 4s2
 * Quantum Numbers:
 * n= 4
 * l= 0
 * ml= 0
 * ms= -1/2

**Strontium**
Was founded by Adair Crawford in 1790. It was name after a Scottish town named Strotian. It's uses are: flares, fireworks, and crimson color. It is obtained from celestite and strontianite.
 * Symbol: Sr[[image:http://periodictable.com/Samples/038.5/s12s.JPG width="190" height="186" align="right" caption="Strontium Dendritic crystal" link="@http://periodictable.com/Samples/038.5/s13.JPG"]]
 * Atomic Number: 38
 * Atomic Mass: 87.62 amu
 * Number of Protons: 38
 * Number of Electrons: 38
 * Number of Neutrons: 50
 * Isotopes:
 * Sr-84, 86, 87, 88: Stable
 * Sr-82: 25.36 days
 * Sr-83: 1.35 days
 * Sr-85: 64.84 days
 * Sr-85m: 1.22 hours
 * Sr-87m: 2.8 hours
 * Sr-89: 50.52 days
 * Sr-90: 29.1 years
 * Sr-91: 9.5 hours
 * Sr-92: 2.71 hours
 * Sr-93: 7.4 minutes
 * Crystal Structure: Cubic
 * Color: Yellowish
 * Electron Configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2
 * Quantum Numbers:
 * n= 5
 * l= 0
 * ml= 0
 * ms= -1/2

**Barium**
Discovered by Sir Humphrey Davy in 1808. It is named from the Greek word Barys which means heavy. Used in medical applications. It comes from barytine and whiterite.
 * Symbol: Ba [[image:http://periodictable.com/Samples/056.1/s12s.JPG width="188" height="178" align="right" caption="Barium Rough octahedra under oil" link="@http://periodictable.com/Samples/056.1/s13.JPG"]]
 * Atomic Number: 56
 * Atomic Mass: 137.327 amu
 * Number of Protons: 56
 * Number of Electrons: 56
 * Number of Neutrons: 81
 * Isotopes:
 * Ba-130, 132, 134, 135, 136, 137, 138: Stable
 * Ba-131: 11.7 days
 * Ba-133: 10.5 years
 * Ba-133m: 1.6 days
 * Ba-135m: 1.2 days
 * Ba-137m: 2.6 minutes
 * Ba-139: 1.4 hours
 * Ba-140: 12.8 days
 * Ba-141: 18.3 minutes
 * Ba-142: 10.7 minutes
 * Crystal Structure: Cubic
 * Color: Silver
 * Electron Configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2
 * Quantum Numbers:
 * n= 6
 * l= 0
 * ml= 0
 * ms= -1/2

Radium
Discovered in 1898 by Pierre and Marie Curie. From Latin word radius meaning ray. It is used to treat cancer. It was found in uranium ores.
 * Symbol: Ra[[image:http://periodictable.com/Samples/088.15/s12s.JPG width="182" height="191" align="right" caption="Radium Broken wristwatch" link="@http://periodictable.com/Samples/088.15/s13.JPG"]]
 * Atomic Number: 88
 * Atomic Mass: 226 amu
 * Number of Protons: 88
 * Number of Electrons: 88
 * Number of Neutrons: 138
 * Isotopes:
 * Ra-222: 38.0 seconds
 * Ra-223: 11.43 days
 * Ra-224: 3.66 days
 * Ra-225: 14.9 days
 * Ra-226: 1600.0 years
 * Ra-228: 5.76 years
 * Crystal Structure: Cubic
 * Color: Silverish
 * Electron Configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2
 * Quantum Numbers:
 * n= 7
 * l= 0
 * ml= 0
 * ms= -1/2

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