AIM: DETERMINING IONIZATION ENERGY AND ELECTRONEGATIVITY OF ELEMENTS DO NOW: 1. LIST IN ORDER OF INCREASING ATOMIC RADII: MAGNESIUM, SILICON, BARIUM, BROMINE 2. DO NOW ON METALS, NONMETALS, AND METALLOIDS WORKSHEET

IONS Positive and negative ions form when electrons are transferred between atoms. Positive and negative ions form when electrons are transferred between atoms. Metals tend to lose electrons; nonmetals tend to gain those electrons Metals tend to lose electrons; nonmetals tend to gain those electrons

ANION An ion with a negative charge An ion with a negative charge (N -3, O -2, Cl -1 ) (N -3, O -2, Cl -1 )

CATION An ion with a positive An ion with a positive charge charge (Na +1, Ca +2 ) (Na +1, Ca +2 )

IONIZATION ENERGY The energy required to remove an electron from an atom. The energy required to remove an electron from an atom. The bigger the ionization energy value the harder to lose an electron (the stronger the atom is holding on to its electron)! The bigger the ionization energy value the harder to lose an electron (the stronger the atom is holding on to its electron)!

FIRST IONIZATION ENERGY The first ionization energy is the energy required to remove the first electron from its atom. The first ionization energy is the energy required to remove the first electron from its atom. First ionization energy tends to decrease from top to bottom within a group and increase from left to right across a period. First ionization energy tends to decrease from top to bottom within a group and increase from left to right across a period.

SECOND AND THIRD IONIZATION ENERGY The second ionization energy is the energy required to remove an electron from an ion with a 1+ charge. The second ionization energy is the energy required to remove an electron from an ion with a 1+ charge. The third ionization energy is the energy required to remove an electron from an ion with a 2+ charge. The third ionization energy is the energy required to remove an electron from an ion with a 2+ charge.

IONIZATION ENERGY – DOWN A GROUP Na has more energy levels (farther from protons) than Li making it easier to lose the outer electron. As you move down a group or family the ionization energy decreases (easier to lose outer electron – more energy levels).

IONIZATION ENERGY – ACROSS A PERIOD Both have the same number of energy levels, but Be has more protons pulling stronger on the outer most electron. As you move across a period, the ionization energy increases (herder to lose outer electron – more protons).

WHICH HAS LOWEST IONIZATION ENERGY? Chlorine Chlorine Sodium Sodium Magnesium Magnesium Argon Argon

ELECTRONEGATIVITY The ability of an atom to attract electrons when the atom is in a compound. The ability of an atom to attract electrons when the atom is in a compound. The ability of an atom to steal an electron from another atom (electron thieves). The ability of an atom to steal an electron from another atom (electron thieves).

ELECTRONEGATIVITY In general, electronegativity values decrease from top to bottom within a group. For representative elements, the values tend to increase from left to right across a period. In general, electronegativity values decrease from top to bottom within a group. For representative elements, the values tend to increase from left to right across a period.

ELECTRONEGATIVITY – DOWN A GROUP Li has fewer levels than sodium making it easier for the protons in the nucleus to grab another atom’s electron. As you move down a group or family the electronegativity decreases (harder to steal electrons – more energy levels). The more energy levels act as a shield.

ELECTRONEGATIVITY – ACROSS A PERIOD Both have the same number of energy levels, but Be has more protons pulling stronger on another atom’s electron. As you move across a period, the electronegativity increases (easier to steal electrons – more protons). *Noble Gases do not have desire to steal electrons because of outer shell!*

WHICH HAS LARGEST ELECTRONEGATIVITY? Chlorine Chlorine Sodium Sodium Magnesium Magnesium Argon Argon

TRENDS (ATOMIC RADIUS ELECTRONEGATIVITY IONIZATION ENERGY)