Tin has a density of 7.31 grams per cubic centimeter (g/cc). This value typically refers to white tin (β-tin), which is the stable and most common allotrope of the element at room temperature.
Understanding Tin's Density
Density is a fundamental physical property that measures the mass of a substance per unit volume. For tin, a density of 7.31 g/cc means that every cubic centimeter of pure tin weighs 7.31 grams. This makes tin moderately dense, falling between lighter metals like aluminum and heavier ones such as lead.
Tin's relatively low melting point and good malleability, combined with its density, contribute to its diverse industrial applications.
Comparing Tin's Density with Other Elements
To put tin's density into perspective, consider how it compares to some other common elements:
| Name | Symbol | Density (g/cc) |
|---|---|---|
| Tin | Sn | 7.31 |
| Manganese | Mn | 7.43 |
| Samarium | Sm | 7.52 |
| Iron | Fe | 7.874 |
As shown, tin's density is quite close to that of manganese and samarium, and slightly less dense than iron.
Factors Influencing Tin's Density
While 7.31 g/cc is the standard density for tin, it's important to note that elemental tin exhibits allotropy, meaning it can exist in different structural forms, each with its own unique density:
- White Tin (β-tin): This is the common metallic form, stable at and above 13.2 °C. Its density is 7.31 g/cc.
- Grey Tin (α-tin): Below 13.2 °C, white tin can slowly transform into grey tin, a non-metallic, brittle powder with a diamond cubic crystal structure. Grey tin is significantly less dense, approximately 5.77 g/cc. This transformation is known as "tin pest" and can cause tin objects to crumble.
Temperature and pressure can also slightly influence the density of a given allotrope, though these changes are typically minor under standard conditions.
Practical Applications Where Density Matters
Tin's density plays a role in various practical applications:
- Alloys: Tin is a key component in many alloys, such as bronze (copper and tin) and pewter (tin, copper, antimony, bismuth). Its density contributes to the overall weight and structural integrity of these materials.
- Soldering: Tin-based solders have specific densities that affect how they flow and adhere during the soldering process, crucial for electronics and plumbing.
- Protective Coatings: Tin plating is used to prevent corrosion in steel cans (tin cans). The relatively low density of tin, combined with its non-toxic nature, makes it a suitable, lightweight coating.
- Ballast and Weighting: While not as dense as lead, tin's density makes it useful in some applications where a specific weight or ballast is required, especially in non-toxic alternatives.
Understanding the density of tin is crucial for engineers, material scientists, and manufacturers working with this versatile metal, ensuring proper material selection and design for a wide range of products.
