9-12.P.1.1. – STUDENTS ARE ABLE TO USE THE PERIODIC TABLE TO DETERMINE THE ATOMIC STRUCTURE OF ELEMENTS, VALENCE NUMBER, FAMILY RELATIONSHIPS, AND REGIONS (METALS, NONMETALS, AND METALLOIDS).

Periodic TableJohn Kovaleski

From the Periodic Table we can determine many things:

Protons, neutrons, electrons, mass number, and atomic number

Number of valence electrons for elements in the main blocks of the Periodic Table

Metallic character of a specific element based on its location on the Periodic Table.

http://www.youtube.com/watch?v=0RRVV4Diomg

How many protons, neutrons, and electrons are in an atom?

ProtonsThe number of protons in an atom is the same as the atomic number. The atomic number is listed above the element abbreviation Silicon has 14 protons.

NeutronsTo determine the number of neutrons in an atom one must subtract the protons from the atomic mass. Magnesium:

24(mass)-12(protons)=12 neutrons

ElectronsThe number of electrons equal the number of protons! Atoms have no overall electrical charge so there must be a balance between the positively charged protons and the negatively charged electrons. Silicon also has 14 electrons

Mass Number and Atomic Number

The mass number, also called the atomic mass number is the total number of protons and neutrons in an atomic nucleus.

The number of protons in the nucleus of an atom determines an element’s atomic number. Each element has a unique number that identifies how many protons are in one atom of that element.

Using the Periodic Table on the next slide, find the mass number and atomic number of hydrogen, phosphorus, and iron.

Using the periodic table, one can classify elements in many ways. One useful way is by metals, nonmetals, and metalloids.

Most of the elements on the periodic table are classified as metals.

Identifying Metallic Character of an Element based on its Location

Metals In the periodic table there is a stair-stepped line starting at Boron

(B) and going all the way down to Polonium (Po). All of the elements to the left of this line except for Germanium (Ge) and Antimony (Sb) can be classified as metals.

In this figure, everything to the left of the green elements are metals. There are different types of metals as well: transition metals, rare earth metals, alkali metals, alkali earth metals, and other metals.

Properties of Metals

Solid (with the exception of mercury (Hg) Mercury can be found in thermometers

Shiny, good conductors of electricity and heat

Ductile: they can be drawn into thin wires

Malleable: they can be easily hammered into thin sheets

Metals tend to lose electrons easily

Nonmetals The elements to the right of the stair-stepped line are classified

as nonmetals. Hydrogen is also classified as a nonmetal

Nonmetals have properties opposite those of metals.

Nonmetals are: Brittle

Not malleable or ductile

Poor conductors of heat and electricity

Gain electrons in chemical reactions

Some are liquids

Metalloids The elements that border the stair-stepped line are classified as

metalloids. These are also known as semimetals. They have properties that are somewhat of a cross between metals and nonmetals.

Metalloids tend to be economically important because of their unique conductivity properties which make them valuable in the semiconductor and computer chip industry. Metalloids only partially conduct electricity.