Objective

The goals of this experiment are:

Grading

You will be assessed on:

Background Information

First, you are going to travel back to 1869 and marvel at how the first periodic law and table were born when only 63 elements had been discovered at the time. A 35 year old professor of general chemistry, Dmitri Ivanovich Mendeleev, at the University of St. Petersburg (now Lennigrad) in Russia was shuffling cards, each labeled with the property of an element, trying to organize his thoughts for his soon-to-be famous textbook on chemistry. He realized that if the elements were arranged in the order of their atomic weights, there was a trend in properties that repeated itself several times!

In order to see and find order among the elements, we must have some general acquaintance with them. Elements are made of matter, and matter is defined as anything that has mass and occupies space. This includes everything that you can see and a lot that you cannot. It follows that in order to distinguish between different types of matter (in other words different elements) we have to assess their properties.

There are two types of properties: intensive and extensive. In the former case, intensive properties do not depend on the how much of an element is present but do include state (whether a substance is a solid, liquid or gas), color and chemical reactivity. Extensive properties depend on the quantity of matter present; mass and volume are extensive properties.

Properties can be further categorized as either chemical or physical. A chemical change describes how the substance may change composition, such as spontaneously by combustion or in combination with other substances. On the other hand, physical changes are those properties that can be measured without changing the composition of the matter. Condensation of steam to water is a physical change.

Introduction

What is there to know about the periodic table? Why is it important? Why does it appear in nearly every science lecture room and lab? Is it just a portrait of an aspect of chemistry or does it serve a useful purpose? Why is the name periodic appropriate? Why is the table arranged in such a way? What are the important features of the table? Does it give order to the approximately 120 known elements?

Relative Reactivity of Metals and the Activity Series

 A superficial glance at the Periodic Table will reveal that all known elements are listed by their chemical symbols. An in depth glance at the Periodic Table yields information on the mass of an atom of the element in atomic mass units (amu) for the molar mass of a mole ( 6.02×10236.02×1023 size 12{6 "." "02" times "10" rSup { size 8{"23"} } } {}) of atoms in grams below the chemical symbol for each element. Above the chemical symbol for each element, there is a second number listed, the atomic number, which gives the number of protons (positively charged particles in the nucleus), or the number of electrons (negatively charged outside the nucleus) for a neutral atom.

Mendeleev arranged the elements in the Periodic Table in order of increasing atomic number in horizontal rows so that elements with similar properties recur periodically (another words they fall directly beneath each other in the Table). The elements in a given vertical column are referred to as a family or group. The physical and chemical properties of the elements in a given family change gradually as one goes from one element in the column to the next. By observing the trends in properties, the elements can be arranged in the order in which they appear in the Periodic Table.

I. Activity Series