The heavy metal lead consists of closely spaced atoms that lead to a high density. Compared to other metals, it is in the higher midfield. Its molecular structure ensures a low material hardness despite its high volume weight, which makes lead a versatile material.
Heaviest member of the carbon group
In the periodic table of the elements, the heavy metal lead belongs to the carbon group together with the elements carbon, silicon, germanium and tin. In the carbon group, lead with the Latin abbreviation Pb for plumbum or the Anglo-Saxon name lead has the highest density at 11.34 grams per cubic centimeter.
- Also read - lead for fishing weights or pour it yourself for New Year's Eve fun
- Also Read - The scrap price for lead fluctuates like a stock market price
- Also read - Painting lead with special coatings
Most elements with a higher density have properties that severely limit their use. Examples are radioactivity such as uranium and rhodium, very high toxicity such as mercury or the high price due to rarity such as gold and titanium. Lead has about half the density of the densest known element, osmium. Lead is less toxic than mercury.
Density of elements and materials
When comparing and classifying the density of lead, the density values of other known and frequently occurring elements and materials help. They are given in kg / dm3 or, as here, in g / cm³:
|concrete||-||1.8 to 2.4|
|cement||-||3.0 to 3.1|
Exploiting the density of lead
Two of the best-known ways of exploiting the high density of lead are as weights, for example in fishing or model making and as radiation protection. In earlier times, the high weight and small volume were also used to weigh down curtains and drapes with a lead cord. However, the toxic properties of lead have made these uses almost disappear.
In model making, lead is mainly used to balance moving and mobile constructions such as vehicles and airplanes. Here, too, the density plays the decisive role. Even small amounts of lead with an expansion of a few cubic centimeters can form the necessary counterweights. A lead cube with the side dimensions of two centimeters weighs about ninety grams.
The density was also used for the weight compensation and taring of car rims. These balance weights are increasingly being replaced by the non-toxic materials steel and zinc. Their lower density, however, requires around a third more space or the number of individual weights.
Bullets and shot
Lead is often used in the form of bullets. The most popular ammunition is lead shot. Different shaped pellets are also used in sport shooting. The high density of lead ensures precise and predictable ballistic trajectories up to around ten meters.
Lead also has sufficient hardness to withstand launch undeformed. For example, a breakthrough on targets can be carried out cleanly and counted. Due to its toxic properties, lead is rarely used as hunting ammunition. Here, too, the density ensures penetrating projectiles.
High density acts as radiation protection
The protective effect against X-rays and other radioactive radiation sources is mainly due to the molecular structure of the lead and its density. Put simply, many atoms that are tightly pressed together allow fewer rays to pass through. Lead is primarily chosen because alternatives with similar or better shielding values, i.e. density, are significantly more expensive. Typical examples are copper, silver and gold.
Despite its density, lead can only "intercept" part of the rays, which is why attempts are still being made to limit X-raying to the most necessary number of applications. Since some lead ores have natural radioactive isotopes, particularly low-radiation lead must be used for the production of radiation protection.
Decrease in density when heated
Scientific measurements show the decrease in the density of lead when heated. As with most other elements, heating leads to greater movement of the atoms or molecules. This creates larger gaps and the density decreases. In the case of lead, however, the change is only significant in a scientific sense and can be neglected in practical application.
The average spatial expansion in heating lead is estimated at 3.44 percent. This volume needs the liquid hot lead more to obtain the same weight after the density decrease.Tips & tricks The density of so-called workflow, which is recovered from Beieltez and acts as a material for the applications of all kinds, is subject to low fluctuations, as there are only between 95 and 98 percent pure workflow. If you encounter hut blaze or finebleing, the material cleaner and thus original density is over 99 percent.