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Bell Work. How do you think the periodic table is arranged and list for me ways in which you think the periodic table used. Or what can it be used for and why is it important?. Periodic Table. Objective: How are elements arranged on the periodic table?. Periodic Table.
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Bell Work • How do you think the periodic table is arranged and list for me ways in which you think the periodic table used. Or what can it be used for and why is it important?
Periodic Table • Objective: How are elements arranged on the periodic table?
Periodic Table • In 1869, Russian chemist Dmitri Mendeleev arranged the elements in order of increasing atomic mass. • However, there were gaps in the table. • In 1914, British scientist Henry Moseley found the number of protons —the atomic number. • When the elements were arranged by atomic number, they fit the pattern in Mendeleev’stable..
Periodic Squares • So the periodic table is arranged by increasing atomic number. • Each Element is Identified by a Chemical Symbol. • Each square on the periodic table includes an element’s name, chemicalsymbol, atomic number, and atomic mass. • For most elements, the chemical symbol has one or two letters. The newest elements have temporary three-letter symbols. • The 1st letter is always capitalized and the 2nd letter is always lower case.
Periodic Squares • Please draw and label the following periodic square!
Arrangement of the P.T. • Each horizontal row of elements is called a period. The chemical and physical properties of elements in a row follow a repeating pattern as you move across the period. • Each vertical column of elements is called a group. Elements in the same group often have similar chemical and physical properties.
Understanding P.T. • Elements are classified as metals, nonmetals, and metalloids, by their properties. • The number of electrons in the outer energy level of an atom is one characteristic that helps determine which category an element belongs in. • The zigzag line on the periodic table can help you recognize which elements belong in which category.
Parts of P.T. Zig-zag line
Metals • Metals are found to the left of the zigzag line. Atoms of most metals have few electrons in their outer energy level. • Most metals are shiny, ductile, malleable, and are good conductors of electric current and thermal energy.
Nonmetals • Nonmetals are found to the right of the zigzag line. Atoms of most nonmetals have an almost complete set of electrons in their outer energy level. • Nonmetals are not shiny, ductile, or malleable, and are poor conductors of electric current and thermal energy.
Metalloids • Metalloids are the elements that border the zigzag line. Atoms of metalloids have about half of a complete set of electrons in their outer energy level. • Metalloids have some properties of metals and some properties of nonmetals. Metalloids are also called semiconductors.
Objective • EXIT TICKET: write on ½ sheet and answer then give to Ms.Jones on way out! • What are the location on the periodic table of metals, nonmetals, and metalloids?
Objective • On ½ sheet of paper answer the following question • List all the major groups of the periodic table by their names.
Groups of P.T. • Group 1 - Alkali metals • Alkali metals are elements in Group 1 of the periodic table. • Alkali metal properties: - group contains metals - 1 electron in the outer level - very reactive - softness, color of silver, shininess, low density
Group 2 - Alkaline-earth metals • Alkaline-earth metals are elements in Group 2. • Alkaline-earth metal properties: - group contains metals - 2 electrons in the outer level - very reactive, but less reactive than alkali metals - color of silver, higher densities than alkali metals
Transition Metals • Transition metals are in Groups 3–12. • Properties of Transition Metals vary widely but include: - groups contains metals - 1 or 2 electrons in the outer level - less reactive than alkaline-earth metals - shininess, good conductors of electric current and thermal energy
Group 13 – Boron • Aluminum is the most common element from Group 13. • Group 13 properties: - group contains 1 metalloid and 5 metals - 3 electrons in the outer level - reactive - solids at room temperature
Group 14 – Carbon • Group 14 properties: - group contains 1 nonmetal, 2 metalloids, and 2 metals - 4 electrons in the outer level - reactivity varies among the elements - solids at room temperature
Group 15 – Nitrogen • Group 15 properties: - group contains 2 nonmetals, 2 metalloids, and 2 metals - 5 electrons in the outer level - reactivity varies among the elements - solids at room temperature (except for nitrogen, which is a gas)
Group 16 – Oxygen • Group 16 properties: - group contains 3 nonmetals, 1 metalloids, and 1 metal - 6electrons in the outer level - reactive - solids at room temperature (except for oxygen, which is a gas)
Group 17 – Halogens • Group 17 properties: - group contains nonmetals - 7 electrons in the outer level very reactive - poor conductors of electric current, never in uncombined form in nature
Group 18 – Noble Gas • Group 18 properties: - group contains nonmetals - 8 electrons in the outer level (except helium, which has 2) - have a full outer shell - unreactive - colorless, odorless gases at room temperature
Hydrogen • The properties of hydrogen do not match the properties of any single group, so hydrogen is set apart: - a nonmetal -1 electron in the outer level - reactive - colorless, odorless gas at room temperature - low density