H6P7: Young's Modulus
Rank the following 3 classes of materials in order of increasing typical Young's Modulus: metals such as copper, plastics such as HDPE (high density polyethelene), and ceramics such as alumina (Al2O3). Do not look up the values of Young's Modulus, instead base your answer on what you know about the structure and chemistry of these classes of materials.
metals,Plastics, ceramics
rank time:________<_________<__________
Noted.
plastic<metal<ceramic
thanks
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To rank the three classes of materials in order of increasing typical Young's Modulus (stiffness), we can consider their structure and chemistry.
1. Plastics such as HDPE (high density polyethylene) have a relatively low Young's Modulus. Plastics are made up of long chains of polymers that are intertwined and have weak intermolecular forces. These chains can easily slide past each other, resulting in lower stiffness compared to metals and ceramics.
2. Metals, such as copper, have a higher Young's Modulus than plastics. Metals have a crystalline structure composed of closely packed atoms that form metallic bonds. These bonds are strong and contribute to the rigidity of the material, making metals more stiff than plastics.
3. Ceramics, like alumina (Al2O3), typically have the highest Young's Modulus among the three classes of materials. Ceramics are characterized by a regular arrangement of atoms and strong ionic or covalent bonds. These materials have a high degree of rigidity and exhibit very little plastic deformation under load, making them stiffer than both metals and plastics.
So, the ranking in order of increasing typical Young's Modulus would be: plastics < metals < ceramics.