Good Morning! To begin today, you will need: 1.3 different colors of writing utensils o colored pencils are up front for your use 2.One blank periodic table o Up front 3.One packet of notes (green) o Up front

The Periodic Table & Periodic Trends

Groups/Families Representative Elements Groups 1A, 2A, 3A, 4A, 5A, 6A, 7A, 8A *CAS vs. IUPAC (old) naming systems label

Periods label

Slide 7 of 31 © Copyright Pearson Prentice Hall Periodic Trends > Trends in Atomic Size The atomic radius is one half of the distance between the nuclei of two atoms of the same element when the atoms are joined. 6.3

Trends in Atomic Size Moving left to right, e- are added to the same energy level, while protons are added to the nucleus The e- are attracted more strongly and are pulled in closer to the nucleus, making the atomic size smaller.

Ions When an atom loses or gains electrons it becomes an ion. A positively (+) charged ion is called a cation (+). – Lost electrons, so has more protons than electrons – Metals want to lose their valence electrons; therefore only metals can be cations. A negatively (-) charged ion is called an anion (-). – Gained electrons, so has more electrons than protons – Non-metals want to gain valence electrons; therefore only non-metals can be anions. label

Ions When atoms gain or lose electrons, they want to get to have a “full” outer energy shell. The octet rule states that elements gain or lose electrons to attain an electron configuration of the nearest noble gas. Metals lose electrons to go down to the previous energy shell, either full at 2 electrons (Li), or 8 electrons. Non-metals gain electrons to fill their outermost shell to 8 electrons.

Which is bigger…. the cation or the original atom? Which is bigger…. the anion or the original atom?

Trends in Ion Size Students label trend on notes

Trends in 1 st Ionization Energy Energy generally increases Ionization Energy: The energy required to remove an electron from an atom.

Ionization Energies

Trends in Electronegativity Electronegativity The ability of an atom of an element to attract electrons when the atom is in a compound.

Things to Remember Atomic Radius – ½ the distance between the nuclei of two atoms of the same element when the atoms are joined Ions – Cation is a positively (+) charged ion (more protons than electrons) – Anion is a negatively charged ion (more electrons than protons) Ionic size – Cations are always smaller than the atoms from which they form – Anions are always larger than the atoms from which they form The trends that exist among these properties can be explained by variations in atomic structure.