Draw atomic structure of H & He as a class.Mass # is the # of protons PLUS the # of neutrons (each equals 1 AMU).Atomic # is equal to the number of protons or electrons (unless charged).What’s the difference between Mass # & atomic #? Atomic mass (round off for mass # p’s + n’s).Atomic # increasing by 1 means it has one more proton than the previous atom.Atomic # increases by 1, so it has 1 more valence electron than the previous family.The table works because it is based on the structure of atoms, especially the valence e-s (outermost shell).Across a row or down a column the elements’ properties change in a predictable way.An element’s properties can be predicted from its location on the table.Elements are now arranged by increasing atomic number.Published his table in 1869 the newelements were discovered within 16 years.He even predicted the properties of new elements.Mendeleev predicted that the blank spaces would be filled by elements that had not yet been discovered.So he moved the cards into the group it best fit. However, this did not always produce similar groups. Patterns appeared when elements were arranged in order of increasing atomic mass.He listed the elements’ known properties.To help him find a pattern he put all of the known information on individual cards.discovered a system for organizing all of the known elements.1860’s a Russian Scientist named Dmitri Mendeleev.Arranged in rows called periods and columns called groups or families.A way of organizing & classifying elements.29 - Complete fill in the blanks portion of blue packet and turn in. 5 and 6 -Complete yellow Birdley Background: Mendeleev’s table and paste onto p. 28 Periodic Table Trends Notes IQ: On the PT, most elements are non-metals, on left hand side metals, on right hand side non-metals on right hand side metals on left hand side. Modern Periodic Table Periodic – means regular, repeated pattern.Ģ/21 p. OQ: Find the only 2 liquid elements on the PT.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |