The document summarizes key aspects of the periodic table and provides information about the elements lithium (Li), cobalt (Co), and strontium (Sr). It explains that Dmitri Mendeleev organized the periodic table based on atomic mass and that elements are arranged with increasing atomic number from left to right. Elements are also grouped based on similar chemical properties, with nonmetals on the right and metals in the middle and left, except for hydrogen at the top left. Brief descriptions of each element include their atomic number, mass, and common uses.

1. The Periodic Table
By Jacquie McCourt
Chemistry, Period 8

2. How was the PeriodicTable started?
Scientists needed a way to organize the elements.
Dimitri Mendeleev (#om Russia) was the first to start
working the periodic table by classifying the elements by
atomic mass.

3. How is the table organized?
The elements are organized by similar chemical
properties.
The groups that are vertical are ca&ed periods, and the
columns that are horizontal are ca&ed groups.

4. Relationships to each other
On the very right side of the periodic, the elements are
nonmetals.
The middle and the le( side of the periodic are a& metals,
except for the top of the le( side, which is hydrogen.
Staring #om the top le(, and going across, the elements
are arranged so that the nest element over has a higher
atomic number than the element that came before it.

5. The Element Li
This is the element for Lithium.
The atomic number 3, and the atomic mass is 6.941.
Lithium can be used for heat transfer applications,
because it has the highest specific heat than any other solid
element.

6. The Element Co
This is the element cobalt.
It has an atomic mass of roughly 58.9, and it’s atomic
number is 27.
Cobalt is used when making extremely powerful magnets.

7. The Element Sr
This is the element strontium.
Strontium has the atomic mass of 87.62, and it’s atomic
number is 38.
Strontium is used for producing glass in color television
picture tubes.

8. Works Cited
Chemistry.About.com. N.p., n.d. Web. 1 Nov. 2012.
Gagnon, Steve. "The Element Lithium." Jlab.org. N.p., n.d. Web. 1 Nov. 2012.
<http://education.jlab.org/faq/index.html>.
"Dynamic Periodic Table." Dynamic Periodic Table. N.p., n.d. Web. 01 Nov. 2012. <http://
www.ptable.com/>.