CH 05- Periodic Trends
CH 05- Periodic Trends • Ionization – any process that results in the formation of an ion • Ion – an atom or group of atoms that has a positive or negative charge. – Cation(meow) – positive ion… electrons have been LOST!!! – Anion – negative ion… electrons have been GAINED!!! • 3 or less valence electrons atoms will lose to become stable • 5 or more valence electrons atoms will gain to become stable
Writing symbols for ions: a) Write the elemental symbol b) Determine if the atom gains or loses valence electrons and how many c) Write the number and the positive or negative sign next as a superscript next to the elemental symbol.
CH 05- Electron configurations of ions Ion Electron Configurations ( main group elements) • Determine the number of electrons the atom needs to gain or lose to become stable. – Add or take away this number of electrons to change the atom’s configuration. – Your configuration will be the same as one of the noble gases
• EX: sodium, fluorine, Sulfur • Isoelectronic – name given to ions that have the same electron configuration a noble gas – metals lose/non-metals gain electrons to be isoelectronic to nearest noble gas.
CH 05- Ionic Radius • IONIC RADII –the radius of an atom that has an overall charge (AKA: the radius of an ion) • Group: increases from top to bottom----the valence electrons get further away from the nucleus~ same as atomic radii H+ Smaller Li + Na + K+ Larger
• period : decreases from left to right – due to increasing nuclear charge(same as atomic radii). Must look at metals and nonmetals(GR15) separately.
CH 05- Ionic Radius vs. Atomic radius METALS ( cations vs neutral atom) Sodium Atom 1s2 2s2 2p6 3s1 Sodium Ion 1s2 2s2 2p6 • Which radii is BIGGER?? NON-METALS ( anions vs neutral atom) Chlorine Atom 1s2 2s2 2p63s2 3p5 • Chlorine Ion 1s2 2s2 2p6 3s2 3p6 • Which radii is BIGGER??
Writing symbols for ions: a) Write the elemental symbol b) Determine if the atom gains or loses valence electrons and how many c) Write the number and the positive or negative sign next as a superscript next to the elemental symbol.
CH 05- Electron configurations of ions Ion Electron Configurations ( main group elements) • Determine the number of electrons the atom needs to gain or lose to become stable. – Add or take away this number of electrons to change the atom’s configuration. – Your configuration will be the same as one of the noble gases
• EX: sodium, fluorine, Sulfur • Isoelectronic – name given to ions that have the same electron configuration a noble gas – metals lose/non-metals gain electrons to be isoelectronic to nearest noble gas.
CH 05- Ionic Radius • IONIC RADII –the radius of an atom that has an overall charge (AKA: the radius of an ion) • Group: increases from top to bottom----the valence electrons get further away from the nucleus~ same as atomic radii H+ Smaller Li + Na + K+ Larger
• period : decreases from left to right – due to increasing nuclear charge(same as atomic radii). Must look at metals and nonmetals(GR15) separately.
CH 05- Ionic Radius vs. Atomic radius METALS ( cations vs neutral atom) Sodium Atom 1s2 2s2 2p6 3s1 Sodium Ion 1s2 2s2 2p6 • Which radii is BIGGER?? NON-METALS ( anions vs neutral atom) Chlorine Atom 1s2 2s2 2p63s2 3p5 • Chlorine Ion 1s2 2s2 2p6 3s2 3p6 • Which radii is BIGGER??
