Periodic Table Trends SWBAT: predict the atomic radius, ionization energy, electronegativity, nuclear charge, and shielding effect of atoms based on the periodic table.

Nuclear Charge 1. The positive charge found in the nucleus 2. The more protons an atom has the greater the nuclear charge 3. Based on atomic number

A. Charge effect The more electrons are on the same ring and the more protons are in the nucleus the smaller the atomic radius Opposite charges attract!!! + +

Atomic Radius (Size of the Atom) Half the distance between two nuclei of atoms of the same element

B. Atomic Radius (Size of the Atom) 1. Across a period atom shrinks (more protons in nucleus, electrons are attracted to nucleus) 2. Down a group atom increases energy levels and gets bigger

C. Shielding Effect 1. Rings positioned between the valence e- ring and the nucleus are shielding rings 2. The higher the shield effect, the larger the atom because the energy levels block the pull of the nucleus.

Size Trend in the periodic Table 3. Size increases in the following way From right to left From top down

Size Trend in the periodic Table What is: The largest element? What is the smallest? Which is larger C or Si Si or Cl

Valence Electrons Bonding electrons located in the highest energy level of an atom. Using the Bohr model, number of electrons in the outer shell. From periodic table, number of valence electrons is equal to the group (column) that it is in. Column 5 = 5 valence electrons. Valence electrons determine how aggressive it is at bonding. Groups 1,2 and 7 are very active bonders (reactive).  Show Alkali metal videos

D. Ionization Energy 1. Ions a. Are elements that have gained or lost electrons b. they have a net + or – charge 2. Energy required to lose electron

Ionization Energy 3. The smaller the atom the larger the ionization energy required to lose electrons.

E. Electronegativity 1. The ability of an atom to attract electrons when bonded with another atom 2. Follows same trend as ionization energy 3. Smaller atoms have a greater pull of electrons because they are closer to the nucleus

B. Atomic Radius (Size of the Atom) 1. Across a period atom shrinks (more protons in nucleus, electrons are attracted to nucleus) 2. Down a group atom increases energy levels and gets bigger

Circle the element with the higher IE: K or Ca Be or Mg F or Br Si or N Se and Te

Bohr’s Model Drawing Every Principal Energy Level or Period adds 1 new ring to the Bohr’s Model Sketch an element from Per 1 and Per 4. Which one has the largest which the smallest atomic radius?

E. Atomic Size Trend within the Periodic Table 1. If you move from left to right within the same period, atomic size decreases 2. Even though atomic number increases!!!