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Discover the structure and properties of elements from the Periodic Table. Learn the history and fun facts about key elements and their significance.
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Periodic Table of Elements • A way of listing the elements. • Elements are listed in the table by the structure of their atoms. • This includes how many protons they have as well as how many electrons they have in their outer shell. • From LEFT to RIGHT and TOP to BOTTOM, the elements are listed in the order of their atomic number. • Atomic number is the number of protons in each atom.
Why is it called the Periodic Table? • It is called “periodic” because elements are lined up in cycles or periods. • From LEFT to RIGHT, elements are lined in rows based on their atomic number (# of protons in the nucleus). • Columns are the number of valence electrons for each atoms. • Elements in each Column have similar properties.
Element Abbreviations • Each element has its own name and abbreviation. • Some are easy to remember, like H for Hydrogen. • Some are a bit harder, like Fe for Iron and Au for gold. • Au comes from the Latin word, “aurum”.
Who invented the Periodic Table? • Proposed by Russian chemist Dmitri Mendeleev in 1869. • Using the table Mendeleev was able to accurately predict the properties of many elements before they were discovered.
Fun Facts about the P. Table • Carbon is unique in that it is known to form up to 10 million different compounds. Carbon is important to the existence of life. • Francium is the rarest element on earth. There are probably no more than a few ounces of it on earth at any given time. Discovered in France in 1939. Used mainly in research purposes. • The only letter not in the P. Table is the letter J. • Helium was first discovered by observing the sun.
Group 1: Alkali Metal • Hydrogen is not considered an Alkali Metal. • Lithium, Sodium, Potassium, Rubidium, Cesium, and Francium. • Shiny, soft, metals. • VERY Reactive • ALL have one valence electrons. • Willing to give away (lose) their one valence electron to form a compound. • Soft enough to cut with a knife. • Will tarnish when exposed to air. • Will react when in contact with water…some will explode! • Malleable, ductile, and good conductors of electricity and heat.
Facts about Alkali Metals • Generally stored in oil, otherwise…BOOM! • Cesium and Rubidium are used to make atomic clocks. Cesium clocks are considered to be MOST accurate of all clocks. • Sodium and Potassium are so important, we cannot have life without them. • Like to form compounds with Halogens • Alkali is derived from the Arabic word for “ashes”. • Alkali metals have odd atomic #s.
Group 2: Alkali Earth Metals • Beryllium, Magnesium, Calcium, Strontium, Barium, and Radium. • Silvery, shiny and relatively soft metals. • 2 valence electrons. • Found in minerals, compounds. • Forms ionic bonds. • These elements burn in various colored flames. • Form solutions with pH greater than 7…forms Bases. • Calcium plays an important role in building strong bones. • Magnesium is used to regulate the body’s temperature.
Transition Metals • Transition metals make up the largest section of the P. Table. • Groups 3-12. • Titanium, Copper, Nickel, Silver, Platinum and Gold • Unique because these elements have incomplete inner subshells. • These metals have different oxidation states. • Forms compounds in different colors. • Often used in industry as catalysts for various reactions.
Boron Group • Group contains one metalloids and five metals. • 3 electrons on the outermost energy level. • Reactive. • Most common element is Aluminum. • The word Boron is derived from the Arabic word Borax.
Halogens • Group 17. • Fluorine, Chlorine, Bromine, Iodine, and Astatine. • All form acids when combined with Hydrogen. • Fairly toxic. • Combine to form Salt. • Halogen comes from the Greek words “hals”, meaning “salt”, and “gen”, meaning “to make.” • Fluorine gas is deadly. • Small amounts of fluoride are used in water and in toothpaste to prevent tooth decay.
Nobel Gases • Group 18. • Atoms have FULL outermost energy level. • Helium, Neon, Argon, Krypton, Xenon, and Radon. • Stable gases…does not form bonds with other elements. • Colorless and Odorless
Facts about Noble Gases • Helium is non-flammable…safe to fill balloons. • Krypton gets its name from the Greek word “kryptos” meaning “the hidden one”. • Most noble gases were discovered by Scottish chemist Sir William Ramsay. • Neon signs do not use just neon gases, but mixture of different noble gases. • Xenon gets its name from the Greek word “xenos” which means “stranger or foreigner.”