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
The Periodic Table Mendeleev was a Russian scientist who is credited with the development of the periodic table – a table that classifies and groups all known elements. Mendeleev knew the properties of the elements, such as colour, density, boiling point, and atomic mass (the average mass of an atom of an element). He created cards for each element and began arranging the elements in vertical columns and horizontal rows. After many months he noticed a pattern occurred when he placed the cards in order of increasing atomic mass (known today as the periodic law). Properties of elements were repeated both within rows and in columns. At the time, there were only 58 known elements. So Mendeleev left spaces in his table assuming an undiscovered element would take its place. He predicted the properties of the “unknown” elements, and within the next sixteen years those gaps were filled in with newly discovered elements that matched precisely with Mendeleev’s predictions! Activity – Chemical solitaire. Page 127. Hand in the arrangement of your best grouping and questions #1-3. Read page 126-128. The modern periodic table (page 441) has elements that are arranged by increasing the atomic number. The periodic table includes the following information for each element: 1) Symbol 2) Element name 3) Atomic number – number of protons an element has in its nucleus. (examples) 4) Atomic mass a. the average mass of an atom of an element. b. = Number of protons + number of neutrons c. examples – such as how many neutrons in F? Work on investigation 2-D on pages 129 -131. (handout BLM 2-10). Answer ALL questions. The periodic table is arranged into: - rows – called periods. The trend within a period is increasing atomic mass. - Columns – called groups or families. The trend within a group is the elements share similar reactivity. BLM 2-11 BLM 2-12 Read chapter. Answer questions #1-4 on page 135.