The weight of an element like tin or lead is a matter both of its atomic weight --- how much an individual atom of the element weighs --- and of its density. The denser the substance, the more mass it contains per unit volume, and the heavier a given chunk of it will be.
Lead has atomic number 82, meaning its nucleus contains 82 protons, and when neutral (not ionized) it has 82 electrons. Electrons make a negligible contribution to the mass of the atom and can be disregarded where atomic weight is concerned. Different isotopes of lead have different numbers of neutrons, so the atomic weight you see listed on the periodic table is actually a weighted average: 207.2 atomic mass units (amu). Tin, by contrast, has atomic number 50 and therefore only 50 protons/electrons. Its atomic weight is 118.710 amu.
An atom of lead weighs more than an atom of tin, but in real life, you'll never encounter a situation where you can isolate a single atom of either element. When chemists want to know how many atoms are present, they use the molar mass, the mass corresponding to 6.022 x 10^23 atoms of that element. The molar mass is just the atomic mass but with units of grams / mole rather than amu. Tin, therefore, has a molar mass of 118.710 grams per mole and lead has a molar mass of 207.2 grams per mole. Once again, a mole of lead weighs much more than a mole of tin.
If you have two equally sized objects made of lead and tin, the difference in weight between these objects is determined by density. Here again, lead has the lead. At room temperature, the density of lead is 11.342 grams per cubic centimeter, while the density of tin is 7.287 grams per cubic centimeter. An object made of lead, therefore, weighs much more than the same object made of tin.
A compound made from lead does not necessarily weigh more than a compound made from tin, however; the weight of each depends on the type of compound and the other atoms it contains. Tin (II) iodide, for example, has a greater molar mass than lead dioxide. Solid objects made from lead and tin both sink in water because the density of both lead and tin at room temperature is much greater than that of water (1 gram per cubic centimeter).
- Photo Credit Jupiterimages/Photos.com/Getty Images
What Is the Weight of Gold?
In the Periodic Table of Elements, gold is represented by the chemical symbol Au, Latin for aurum, meaning shining dawn. Known for...
What Is Tin Metal?
Tin is a silvery, thin and light element in the Earth's crust that can be easily molded and melded. It is flexible...
Atomic Number Vs. Atomic Density
Atomic density means the number of atoms per unit volume. The atomic number of an element represents the number of protons in...
How to Figure Weight of Lead by Volume
Each element and compound has a density that relates the weight and volume of that material. Factors such as temperature and pressure...
How to Convert Grams to AMU
Both gram and AMU (atomic mass unit) are units of measure. The gram is a much larger unit than the AMU. It...
How to Melt Lead Weights
Melted lead weights can be reused to make fishing lures, sinkers and hunting bullets. To melt lead weights, you need a heat...
How to Calculate the Mass Defect
If you add up the individual neutrons and protons in an atomic nucleus, their mass is less than the mass of the...
The Composition of Tin Cans
Tin cans have been used for food storage since the beginning of the 19th century. The cans provide an airtight container which...
Difference Between Lead & Pewter
Lead and pewter can be quite similar in appearance. And they have some similar characteristics. Each can be made shiny, but they...
List of Chemistry Formulas
Chemistry is the science of matter--how it behaves, what it is and how it forms. This study impacts all parts of everyday...
A Substitute for Lead Alloy
The U.S. government has recognized lead as a toxic material that could cause harm to humans and regulates the use of the...