DEVELOPMENT OF MODERN TABLE METALS VS. NONMETALS GROUPS VS. PERIODS TRENDS GLENCOE SCIENCE CHEMISTRY Periodic Table

Development of the Modern Periodic Table Antoine Lavoisier (late 1700s)  Organized the 33 known elements into four categories.  List what the categories are and give examples: (look on pg 174, table 6.1)  ________________________________________________ John Newlands (look on pg 176, table 6.2)  Arranged elements by ___________________________________  Noticed the repetition of properties every ______________________  Created the law of ___________ which means (look on pg. 175) ___________________________________________________

Development of the Modern Periodic Table Lothar Meyer  Demonstrated a connection between ________________ and _______________________  Arranged the elements in order of increasing ___________ Dmitri Mendeleev  Demonstrated a connection between ________________ and _______________________  Arranged elements in order of _____________________  ________ the existence and properties of _____________ elements Who usually gets more credit for their work?

Cont. Henry Moseley  Discovered that atoms contain a unique number of ________ called the _______________________  Arranged elements in order of increasing ______________________________ which resulted in a _________________ of properties

The Modern Periodic Table Consists of squares or boxes Arranged in order of increasing ______________ Columns are called ________ or ____________  There are _____ columns numbered from left to ________  Columns also have names for their families. On your periodic table, write the names above each column. Rows are called ___________  There are ____ rows.  But there are two rows that seem to be out of place. They are the ______________ and _____________ series

These Are the Elements

Metals (pg. 177) Nonmetals (pg. 179) Location  Groups 1-12; part of groups  Always left of the stair- step Physical Properties  List physical properties of metals Chemical Properties  List chemical properties Location  Most are _____ of the stair- step except _____  Found in groups _________________ Physical Properties  List physical properties of nonmetals Chemical Properties  List chemical properties Metals vs. Nonmetals

Metals, Nonmetals, Metalloids

There is a zig-zag or staircase line that divides the table. Metals are on the left of the line, in blue. Nonmetals are on the right of the line, in orange.

Metals Metals are lustrous (shiny), malleable, ductile, and are good conductors of heat and electricity. They are mostly solids at room temp. What is one exception?

Nonmetals Nonmetals are the opposite. They are dull, brittle, nonconductors (insulators). Some are solid, but many are gases, and Bromine is a liquid.

Metalloids Metalloids, aka semi- metals are just that. They have characteristics of both metals and nonmetals. They are shiny but brittle. And they are semiconductors. What is our most important semiconductor?

Periodic Table Trends  Atomic numbers are at the ________ of each square and go in order  Each element has its own symbol and an average atomic _____________  Elements tend to get ___________ in atomic radius as you go down the group.  Atomic number gets larger as you go across the row from _________to _________ (period) and down the _______.  Some of the elements are named after ________, _______, countries, and their Latin or Greek names.  Hydrogen and Helium are separate from the other elements in their group. Why?

The Periodic Law Atoms with similar properties appear in groups or families (vertical columns) on the periodic table. They are similar because they all have the same number of valence (outer shell) electrons, which governs their chemical behavior.

Periodic Trends The first and most important is atomic radius. Radius is the distance from the center of the nucleus to the “edge” of the electron cloud.  Atomic radii are usually measured in picometers (pm) or angstroms (Å).  A picometer is 1 x m.  An angstrom is 1 x m.

Atomic Radius – Family Trend The trend for atomic radius in a vertical column is to go from smaller at the top to larger at the bottom of the family. Why? With each step down the family, we add an entirely new principal energy level (PEL) to the electron cloud, making the atoms larger with each step.

Atomic Radius On your help sheet, draw arrows like this:  Increase

Atomic Radius – Help Sheet. How big is an atom? Atomic radius decreases across a period from left to right due to increased effective nuclear charge (ENC). Atomic radius increases down a group because of the addition of more energy levels.

Atomic Radius Arrange the following sets of atoms in order of increasing size: Se, Sr, Ne: Na, Ba, F: Ne < Se < Sr La, C, Pd

Review so far Atoms/Chaos/Chaos.htm Atoms/Chaos/Chaos.htm

Ions Elements can __________ or ___________ electrons. Atoms that gain electrons:  Nonmetals  Called anions Atoms that lose electrons:  Metals  Called cation To gain or lose electrons, __________ is required. CW/HW complete ionization practice worksheet.

Ions Here is a simple way to remember which is the cation and which the anion: This is a cat-ion. This is Ann Ion. He’s a “plussy” cat! She’s unhappy and negative. +

Cation Formation 11p+ Na atom 1 valence electron Valence e- lost in ion formation Remaining e- are pulled in closer to the nucleus. Ionic size decreases. Result: a smaller sodium cation, Na + Cations are always smaller than the original atom.

Anion Formation 17p+ Chlorine atom with 7 valence e- One e- is added to the outer shell. Effective nuclear charge is reduced and the e- cloud expands. A chloride ion is produced. It is larger than the original atom. Anions are always larger than the original atom.  Electrons are added to the outer PEL.

Ionization Energy The energy required to remove an electron from an atom is ionization energy.  Measured in kilojoules, kJ The larger the atom is, the easier its electrons are to remove. Ionization energy and atomic radius are inversely proportional.

Ionization Energy (Potential) Draw arrows on your help sheet like this: Increase 

Electronegativity Electronegativity is a measure of an atom’s attraction for another atom’s electrons. Generally, metals are electron givers and have low electronegativities. Nonmetals are electron takers and have high electronegativities. What about the noble gases?

Electronegativity Your help sheet should look like this: 0 Increase 