How would you explain all states of matter?

1 Answer
Dec 20, 2016

There are two main factors that determine the state of a substance:

  1. The forces holding the particles together,
  2. The kinetic energy of the particles.

Explanation:

There are two main factors that determine the state of a substance:

  1. The forces holding the particles together,
  2. The kinetic energy of the particles.

First of all, the forces. If there were no forces between particles, all substances would be gases, thus are necessary in liquids and solids. The stronger the force, the more kinetic energy is required to pull the particles apart.

These forces are determined by the electronegativity of the substance:

Oppositely charged particles - Ionic bond
- Electronegativity of #>1.7#.
- Have an electrostatic attraction that holds the molecule together.
- A very strong bond, and usually results in the state of a solid at room temperature.

Polar bonds
- Electronegativity of #0.5 -> 1.7#.
- Molecules have a permanent dipole effect due to partial charges.
- Dipole-dipole forces are not as strong as ionic bonds.
- Can exist as liquids (#H_"2"O#) or even gases (#NH_"3"#) at room temperature.

Non-polar bonds
- Electronegativity of #0.5>#.
- Held together by weak forces (temporary dipoles).
- Usually exists as gases at room temperature.

Secondly, the kinetic energy of the particles, also known as temperature of substance. By adding energy to the substance (heating it up), the particles are excited and gradually, the forces' strength diminish.

When the strength of attraction weakens, particles are able to translate and rotate themselves, rather than just vibrate. Eventually, the attraction is so weak (with higher kinetic energy), that there is a minuscule amount, resulting in a gas.

Solids have very little kinetic energy, liquids have a moderate amount, and gases have a lot.

Hope this helps :)