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Particles are held together by inter-particular forces. Above absolute zero, 0K all particles have energy. The energy can be vibrational as in solids, and rotational and translational kinetic energy. As the temperature increases the vibrational energy increases to such a point that the inter-particular forces are broken. The solid then usually turns to liquid as it loses its structure and then eventually a gas. Some solids can sublimate ie turn directly to a gas and omit the liquid phase.
Example:
Water molecules, H2O are held together by polar forces called "hydrogen bonding". The slightly positive hydrogens are attracted to the negative oxygens of neighbouring molecules. That is why water is a liquid at room temperature despite the small size of the molecule. Heating the water allows the molecules to vibrate breaking the hydrogen bonding. At around 100 oC all of the bonds have enough energy to break and the liquid turns to a gas.
What else can I help you with?
What is the phase change in which substance change form a gas to aliquid?
The phase change in which a substance changes from a gas to a liquid is called condensation. It occurs when the temperature of the gas decreases to reach its condensation point, causing the gas molecules to come together and form a liquid.
Why does temperature no change during energy phase change?
During a phase change, the heat transferred to a substance is used to break intermolecular forces (latent heat), and thus the temperature of the substance does not change. The opposite also occurs: heat is transferred from a substance during a phase change without a decrease in temperature as intermolecular bonds form.
How do energy and changes in energy change the state of matter?
Energy can change the state of matter by breaking or forming intermolecular bonds. Adding energy to a substance can overcome the forces holding the molecules together, leading to a phase change (solid to liquid, liquid to gas). Removing energy from a substance can cause the molecules to come closer together, resulting in a phase change in the opposite direction.
What rule can you state about the relationship between phase changes and temperature?
As the temperature increases, the phases change from having the slowest amount of molecules to having the fastest amount of molecules (solid-liquid-gas)
What is a substance called when it change from solid to liquid?
This physical phenomenon (a change of phase) is called melting; during melting the chemical nature of molecules is not changed.
What are two physical changes that cooling a hot substance may resuit in?
Cooling a hot substance may result in the molecules slowing down, leading to a decrease in volume and contraction of the substance. Additionally, cooling can cause a phase change, such as from a liquid to a solid, as the substance reaches its freezing point.
When a substance changes from one physical form to another you say the substance has had a what?
When a substance changes from one physical form to another, you say the substance has had a phase change or undergone a phase transition.
What occurs when a substance moves from liquid to gas?
This change of phase is called vaporization and is a physical phenomenon; the chemical nature of the molecules was not changed.
What are the phase changes processes taking place when a substance is in equilibrium between liquid and gas phase?
Evaporating and condensing
How does the vapor pressure of a substance change with temperature?
The vapor pressure of a substance increases with temperature. As the temperature rises, more molecules have enough energy to escape from the liquid phase and enter the gas phase, leading to an increase in vapor pressure.
What causes a substance to change a phase?
change in temperature
Why does the temp of water not increase during a phase change?
During a phase change, the energy that is added or removed from the water is used to change the arrangement of water molecules rather than increase the temperature. This energy is used to break or form intermolecular bonds between the molecules, leading to a change in state (solid, liquid, gas) rather than a change in temperature.
