A low density solid is a material that has a relatively small mass for its volume; in simpler terms, it feels light for its size.
To understand this better, let's break down the concepts of mass, volume, and density:
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Mass: The amount of matter in an object, often measured in grams (g) or kilograms (kg).
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Volume: The amount of space an object occupies, often measured in cubic centimeters (cm³) or cubic meters (m³).
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Density: A measure of how much mass is contained within a given volume. It is calculated by dividing mass by volume (Density = Mass / Volume).
Therefore, a solid with low density means that its mass is small compared to the amount of space it takes up. This suggests that the atoms or molecules within the solid are either lightweight or spaced far apart, or a combination of both.
Examples of Low Density Solids:
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Pumice: A volcanic rock that is so porous (full of holes) that it can often float on water. The numerous air pockets significantly reduce its overall density.
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Aerogel: A synthetic solid material that is extremely lightweight and porous. It's made by removing the liquid component from a gel and replacing it with gas.
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Wood: Certain types of wood, especially balsa wood, have relatively low density due to their cellular structure and the presence of air pockets.
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Styrofoam (Expanded Polystyrene): This material is lightweight because it's mostly air trapped within a solid polymer matrix.
Factors Affecting Density:
- Type of Atoms/Molecules: Lighter atoms and molecules naturally contribute to lower density.
- Arrangement of Atoms/Molecules: How tightly packed the atoms or molecules are significantly impacts density. A loose, porous structure leads to lower density.
- Presence of Air Pockets or Voids: If a solid contains a large number of air pockets, its overall density decreases dramatically.
In summary, a low density solid is characterized by a light weight relative to its size due to the nature and arrangement of its constituent materials.
