When things are heated they are receiving energy, which causes the particles within the substance (in this case, custard) to want to increase their velocity (aka speed) the problem with this is that they will keep bumping into other particles which also have high velocity, keeping the overall object generally stationary. On the atomic level (very small scale) all the particles are vibrating at a magnitude equivelent to the energy they have gained.
Also the chemicals within the custard may gain enough energy to break their inter-molecular forces (aka Van der Waals' forces) which hold molecules within the custard together. If heated high enough the atoms may gain enough energy to overcome the bond energy holding them together in the form of molecules... If these break the custard will boil off into the atmosphere.
The particles in a liguid are bonded (not as strongly as a solid which is why it flows.) when it is heated the particles vibrate and eventually the bonds break and the particles break away. This is evaporation.
The speed of the gas particles will increase as they are heated. That is why the pressure in a container increases. The particles are hitting the walls of the container with more force as they are heated.
they get excited and move around faster
The particles start moving faster and the matter expands.
When a substance is heated, the kinetic energy of its particles increases. This leads to the particles moving faster and colliding more frequently with each other and the container they are in.
Its particles acquire greater kinetic energy.
When a gas is heated, the kinetic energy of the gas particles increases. This causes the particles to move faster and farther apart, leading to an increase in pressure and volume. Heating a gas also increases the average speed of the gas particles.
The energy of its particles increases, so as the particles speed up move faster causing its heating up.
when water is heated the particles speed up, therefore gaining kinetic energy. the faster the particles move the further apart they become, therefore leading to the possibility of changing state. such as water to water vapor or ice to water.
When a solid is heated, the particles gain energy, leading to increased movement and vibration. This causes the particles to expand, leading to an increase in volume. Conversely, when a solid is cooled, the particles lose energy, resulting in decreased movement and contraction, which decreases the volume of the solid.
When a gas sample is heated, the particles move faster and collide more frequently with each other and the walls of the container. This increased movement and collisions lead to an increase in the pressure and volume of the gas.
When solids are heated, their particles absorb energy and vibrate more vigorously, causing the solid to expand. This increase in kinetic energy can lead to the solid eventually melting into a liquid, as the particles break free from their fixed positions.