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Why Is the Periodic Table Important? The modern periodic table has changed since Mendeleev's original table, yet both the first tables and the modern table are important for the same reason: The periodic table organizes elements according to similar properties so you can tell the characteristics of an element just by looking at its position on the table. Before all the naturally occurring elements were discovered, the  periodic table  was used to predict the chemical and physical propertiesof elements in the gaps on the table. Today, the table can be used to predict properties of elements yet to be discovered, although these new elements are all highly radioactive and break down into more familiar elements almost instantly. The table is useful for modern students and scientists because it helps predict the types of chemical reactions that are likely for an element. Rather than memorize facts and figures for each element, a quick glance...

This popular chemistry demonstration is often called turning water into wine or water into blood. It's really asimple example of a pH indicator. Phenolphthalein is added to water, which is then poured into a second glass containing a base. If the pH of the resulting solution is right, you can make the water turn from clear to red to clear again, as long as you like. Here's How: Sprinkle sodium carbonate to coat the bottom of a drinking glass. Fill a second glass halfway full of water. Add ~10 drops phenolphthalein indicator solution to the water. The glasses can be prepared in advance. To change water into wine or blood, pour the water with indicator into the glass that contains the sodium carbonate. Stir the contents to mix the sodium carbonate, and the water will change from clear to red. If you like, you can use a straw to blow air into the red liquid to change it back to clear. The principle is the same as for thedisappearing ink formula. Phenolphthal...

Bromine Atomic Number:  35 Symbol:  Br Atomic Weight:  79.904 Electron Configuration: [Ar]4s 2 3d 10 4p 5 Word Origin: Greek bromos:  stench Element Classification: Halogen Discovery:  Antoine J. Balard(1826, France) Density (g/cc):  3.12 Melting Point (°K):  265.9 Boiling Point (°K):  331.9 Appearance:  reddish-brown liquid, metallic luster in solid form Isotopes:  There are 29 known isotopes of bromine ranging from Br-69 to Br-97. Magnetic Ordering:  nonmagnetic Electrical Resistivity (20 °C):  7.8×1010  Ω·m Thermal Conductivity (300 K):  0.122  W·m−1·K−1 CAS Registry Number:  7726-95-6

Zinc Atomic Number:  30 Symbol:  Zn Atomic Weight:  65.39 Discovery:  known since prehistoric time Electron Configuration:  [Ar] 4s 2  3d 10 Word Origin:  German  zinke : of obscure origin, probably German for tine. Zinc metal crystals are sharp and pointed. It could also be attributed to the German word 'zin' meaning tin. Isotopes:  There are 30 known isotopes of zinc ranging from Zn-54 to Zn-83 . Zinc has five stable isotopes: Zn-64 (48.63%), Zn-66 (27.90%), Zn-67 (4.10%), Zn-68 (18.75%) and Zn-70 (0.6%). Properties:  Zinc has a melting point of 419.58°C, boiling point of 907°C, specific gravity of 7.133 (25°C), with a valence of 2. Zinc is a lustous blue-white metal. It is brittle at low temperatures, but becomes malleable at 100-150°C. It is a fair electrical conductor. Zinc burns in air at high red heat, evolving white clouds of zinc oxide. Uses:  Zinc is used to form numerous alloys,inc...

Definition: A carbon-carbon double bond is a double bond between two carbon atoms in a molecule. .Examples: Ethylene (C2H4) is a hydrocarbon with a carbon-carbon double bond.