2 Chemical BehaviorsScientists observe that elements within the same group have similar behaviors.It was proposed that the number and position of electrons found in an atom must have an effect on chemical behaviors.
3 The Bohr ModelThe Bohr Model represents atoms with their electrons in successive energy levels surrounding the nucleus.Each energy level has a limited capacity to hold electrons. (2-8-8)
4 Sample Bohr Model Consider aluminum (Al): The nucleus is drawn in the center.13 protons14 neutrons13 p+13 electrons14 n0The first energy level holds only 2 electrons.3 valence electronsThe second and third energy levels hold only 8 electrons.
5 Bohr Model ComparisonDraw and compare Bohr Models of lithium (Li) and sodium (Na).How many valence electrons are present in each atom?Elements in the same group have the same number of electrons available for bonding.
6 Bohr Model Practice A B C D 1) Which Bohr Model below represents an atom of oxygen?ABBCD
7 Bohr Model Practice A B C D 2) Which Bohr Model below represents an atom of sulfur?ABCCD
8 Bohr Model Practice3) Draw Bohr Models of the following atoms (write-in protons & neutrons):silicon-29nitrogen-14magnesium-24phosphorus-31
9 Bohr Model Practice4) Which of these four atoms would most likely have similar chemical behaviors?silicon-29nitrogen-14magnesium-24phosphorus-31N and P