1.What two things happen to particles in a substance when the substance is heated?
2. What are the three most common states of matter on Earth?
3. Why does a liquid take the shape of whatever container it is in but does not expand to fill the container completely?
4. A certain pure oil solidifies at 5.0°C. What temperature does it melt at?
5. What happens to the particles in liquid water when the water boils into steam?
2. gas, solid, liquid
3. It seeks the lowest level.
5. The water particles move so fast that they escape the liquid and become a gas. Foreign particles are deposited out.
1. When a substance is heated, two main things happen to its particles: they gain energy and they move faster. Heating a substance causes its particles to absorb thermal energy, which increases their kinetic energy. As a result, the particles move more rapidly and have greater freedom of movement within the substance.
To understand why this happens, you can consider the kinetic theory of matter. According to this theory, particles in a substance are in constant motion. When energy is added in the form of heat, the average kinetic energy of the particles increases, causing them to move more vigorously.
2. The three most common states of matter on Earth are solid, liquid, and gas. These states are defined by the arrangement and movement of their particles:
- In a solid, particles are tightly packed together and have fixed positions. They vibrate in place but do not move freely.
- In a liquid, particles are still close together but have more freedom of movement. They can slide past each other but are still contained within the volume of the liquid.
- In a gas, particles are more spread out and move independently at high speeds. They have no fixed positions or definite volume, and they can freely fill any container.
These states of matter can be observed and differentiated based on their physical properties such as shape, volume, and the ability to flow.
3. A liquid takes the shape of the container it is in because its particles have the ability to move and flow freely, allowing them to adapt to the shape of the container. However, a liquid does not expand to completely fill the container because there are intermolecular forces acting between the particles, which keeps them relatively close together.
These intermolecular forces, such as van der Waals forces or hydrogen bonding, exert attractive forces between the particles of a liquid and create a certain degree of cohesion. This cohesion helps the liquid maintain its volume and prevents it from completely spreading out to fill the container.
4. The melting point of a substance is the temperature at which it changes from a solid to a liquid state. In this case, the pure oil solidifies at 5.0°C, which means it changes from a liquid to a solid state at that temperature. To determine the temperature at which it melts, you need to find its melting point.
The melting point and freezing point of a substance are the same, as they refer to the phase transition between a solid and a liquid. So, the temperature at which the oil melts would also be 5.0°C.
5. When water boils and turns into steam, the particles in liquid water gain even more energy and move even faster. This process requires the addition of enough heat energy to overcome the intermolecular forces within the liquid. As the heat energy is absorbed, the water molecules acquire enough energy to break the intermolecular bonds, allowing them to escape from the liquid phase and enter the vapor phase.
The water molecules, when in the gas phase as steam, are further apart and have much greater freedom of movement compared to the liquid state. They move rapidly and independently, filling up the space available to them. The transformation from liquid to gas is a result of the increased kinetic energy and movement of the water molecules during the boiling process.