Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Alkali metal wikipedia , lookup
Boron group wikipedia , lookup
Group 12 element wikipedia , lookup
Dmitri Mendeleev wikipedia , lookup
Alkaline earth metal wikipedia , lookup
Group 3 element wikipedia , lookup
Period 6 element wikipedia , lookup
Period 3 element wikipedia , lookup
Station 1: The Periodic Table 1a. Students know how to relate the position of an element in the periodic table to its atomic number and atomic mass. 1b. Students know how to use the periodic table to identify metals, semimetals, non-metals, alkali metals, alkaline earth metals and transition metals and halogens. 1c. Students know the nucleus of the atom is much smaller than the atom yet contains most of its mass. 1d. Students know how to use the periodic table to draw atoms and determine the number of electrons available for bonding. 1e. Students know how to use the periodic table to create an ion and can explain the trends of ionization energy for each atom. Write 2-3 sentences to describe each of the unit objectives below: 1. Describe how you would identify an element from its atomic number and/or atomic mass. 2. What are electronegativity and ionization energy? 3. Periodic property: Identify the trends (on the periodic table) in electronegativity and ionization energy and explain why they exist. 4. What is the atomic radius of an atom? 5. Periodic property: Identify the periodic trend in atomic radius and explain why it exists. 6. Explain how and why the trends in atomic radius and ionization energy/electronegativity are related. 7. Explain how you would identify metals, non-metals and semimetals (metalloids) using the periodic table. 8. Explain how you would identify the alkali metals, alkaline earth metals, halogens, noble gases, and transition metals using the periodic table. 9. Describe periods and groups on the periodic table. 10. Periodic property: Describe how you would use the periodic table to determine the number of valence electrons on an element, and discuss why valence electrons are important. 11. Periodic property: Explain how you would use the periodic table to identify the ion (positive or negative) an element forms. Station Activity: Complete the following crossword. Periodic Table (std. 1.a – 1.d) How are elements arranged on the periodic table? Elements are arranged in order of increasing atomic number. What is the atomic number? The atomic number is the number of protons in the nucleus of the element. It is located at the top of the element box in the periodic table. What is the element box? The element boxes are the boxes that contain the different elements of the periodic table. Atomic # (number of protons) 11 Na Sodium 22.99 Element symbol Element name Ave. Atomic Mass How are the element boxes arranged in the periodic table? o The boxes are arranged according to atomic number. o As you go from left to right of the periodic table the atomic number increases. o As you go from top to bottom of the periodic table the atomic number also increases. What are other trends of the periodic table? o One other trend is atomic mass. o As you go from left to right and top to bottom of the periodic table, the atomic mass generally increases. There are some exceptions to this rule. Co to Ni How are elements classified on the periodic table? o There are three classes of elements are 1) metals electrical conductors, have luster, ductile, malleable. They are located to the left of the stair-step line of the periodic table. Metallic character increases from right to left and from top to bottom 2) nonmetals Generally brittle and non-lustrous, poor conductors of heat and electricity Some nonmetals are gases, some are solids, one is a liquid. Nonmetals are located to the right side of the stair-step line on the periodic table 3) metalloids Have properties that are between metals and nonmetals. Semi-metals/Metalloids are located on the stair step line in the periodic table. How are elements grouped in the periodic table? o Elements are grouped in vertical columns. These columns are also known as groups or families. o Elements are grouped in these columns/families based on the number of valence electrons (outer-shell electrons). o Each of the groups are numbered 1-18. How are groups identified? o Groups can be identified in two different ways. By number and name. Group 1 is also known as the Alkali Metals (except H). Group 2 is known as the Alkaline Earth Metals. Group 17 is known as the Halogens. Group 18 is known as the Noble Gases. o Elements that lie in column numbers 3--12 are known as the Transition Metals. Each element can form ions with several different charges and “transition” between them. Ex: Fe can be Fe+2 or Fe+3 Examples are gold, copper, silver. What are the trends in the periodic table? o The trends in the periodic table can be described of from left to right and top to bottom. Atomic size (atomic radius) decreases from left to right and top to bottom. The atomic radius is the distance between the nucleus and the valence shell (outer shell). Ionization energy increases from left to right and decreases from top to bottom. Inonization energy (IE) is the energy required to remove an electron. o IE increases from left to right because the elements increase in nuclear charge in this direction. o IE decreases from top to bottom because as the atom’s shells get further away from the nucleus they are less attracted to it. Electronegativity increases from left to right and decreases from top to bottom Electronegativity is the tendency for an atom to attract electrons to itself when it is chemically combined with another element. o Metals are at the left of the table and they let their electrons go easily Thus, they have low electronegativity. At the right end are the nonmetals who want more electrons so they try to take them away from others thus, they have high electronegativity. o Electronegativity decreases from top to bottom because the atomic radius increases from top to bottom because the electrons are less shielded from the nucleus so they feel the attraction stronger. How is the periodic table used to determine the electrons available for bonding? o The column number (1-18) indicates the number of valence electrons. Valence electrons are the electrons on the outer shell of the atom -- the electrons involved in bonding. Elements in column 1 have 1 valence electron, 2 have 2 valence electrons; skip ten columns (the transition metals); Column 13 elements have 3 valence electrons, etc. Elements bond to fill their valence shells. Every element wants to have a full outer shell to become stable (8 electrons). All elements except those that lie in column 18 will either share or gain/lose valence electrons to become full. Metals and Non-metals will combine through an ionic bond in which they exchange electrons. Metals give electrons and become positively charged. A positively charged element is called a cation. Non-metals receive electrons and become negatively charged. A negatively charged element is called an anion. Non-metals will combine through a covalent bond in which they share electrons. Metals will combine through metallic bonds in which their electrons are delocalized.