Download
1 / 15
170 likes | 226 Vues
Periodic Table of Elements. 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.
E N D
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.”
