What holds material things together?

1. 66

   Tusitala Tomposted 10 years ago

   What holds material things together?
   
   We know that liquids will fall under gravity and take the shape of whatever contains them.  We know that gas expands until it fills the entire space.  However, a shoe, a chair or a human body stays the same shape whether they're in a room, a cave, or parked outside in the weather.  We could say that they slowly change; disintigrate, but what keep then consant for so long?

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2. 91

   melporposted 10 years ago

   Mr. Tom, it is the strong and weak nuclear forces in atoms that keep material together. Water is only a fluid because of the weak hydrogen- oxygen bond formed between seperate water molecules when the slightly positive charged hydrogen atom of one water molecule comes near a slightly negative charged oxygen atom of another water molecule. When energy (heat) is added to water molecules, the heat is absorbed by the molecules and they begin to vibrate faster and faster until there is sufficient force to break that hydrogen-oxygen bond between the water molecules. Once that happens, the freed water molecules escapes as gas (water vapors) into the air.

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   1. 66

      Tusitala Tomposted 10 years agoin reply to this

      From this I deduce, Melpor, that when energy is taken away from water the molecules vibrate slowler and the bonds between the molecules grow stronger - hence, ice. What happens when and if vibration stops?

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3. 94

   melbelposted 10 years ago

   Various intermolecular forces hold things together.
   
   Hydrogen bonding is one type of intermolecular force.
   
   Dipole-dipole forces (where permanent dipoles... or unequal sharing of electrons hold neighboring molecules together) are another type. Think of two water molecules interacting here.
   
   Van der Waals forces (temporary dipoles due to shifts in where electrons are concentrated.. these happen all the time.)

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