Chapter 1 - Solids, liquids and gases Flashcards
What are the three states of matter?
Solid, liquid and gas
What are the characteristics of solids?
Solids have a regular arrangement of atoms. The particles vibrates about a fixed position, are very close together and have low energy. They have a high density.
What are the characteristics of liquids?
Liquids have a random arrangement of atoms. The particles move around each other, are close together and have greater energy than solids. They have a medium density.
What are the characteristics of gases?
Gases have a random arrangement of atoms. The particles move quickly in all directions, are far apart and have the highest energy. They have a low density.
What is melting?
Melting occurs when a solid changes into a liquid. It requires heat energy which transforms into kinetic energy, allowing the particles to move. It occurs at a specific temperature known as the melting point.
What is freezing?
Freezing occurs when a liquid changes into a solid. The melting and freezing point of a pure substance are the same. It requires a significant decrease in temperature or loss of thermal energy and occurs at a specific temperature.
What is boiling?
Boiling is when a liquid changes into a gas. It requires heat which causes bubbles of gas to form below the surface of a liquid, allowing for liquid particles to escape from the surface and within the liquid. It occurs at a specific temperature known as the boiling point.
What is evaporation?
Evaporation occurs when a liquid changes into a gas and occurs over a range of temperatures. Evaporation occurs only at the surface of liquids where high energy particles can escape from the liquids surface at low temperatures, below the boiling point of the liquid. The larger surface area and the warmer the liquid surface, the more quickly a liquid can evaporate.
What is condensation?
Condensation occurs when a gas changes into a liquid on cooling, and it takes place over a range of temperatures. When a gas is cooled, its particles lose energy and when they bump into each other, they lack the energy to bounce away, instead they group together to form a liquid.
What is the relationship between temperature and kinetic energy?
When substances are heated, the particles absorb thermal energy which is converted into kinetic energy. Increasing the temperature increases the kinetic energy of each particle. This causes particles to move faster and spread out more. This will cause more frequent collisions.
What happens when you heat a solid?
Heating a solid causes its particles to vibrate more. As the temperature increases, the particles vibrate so much that the solid expands until the structure breaks. This is when a solid melts into a liquid.
What happens when you heat a liquid?
Heating a liquid causes its particles to move more and spread out. Some particles at the surface gain sufficient energy to overcome the intermolecular forces. This is when a liquid starts to evaporate. When the boiling point is reached, all of the particles gain enough energy to escape and the liquid boils into a gas
Increasing temperature diagram
Decrease temperature diagram
What is the relationship between the volume of a gas and temperature?
The volume of a gas increases as temperature increases
What is the relationship between pressure and volume?
Pressure increases as volume decreases. Gaseous particles are in constant and random motion. The pressure that a gas creates inside a closed contained is produced by the gaseous particles hitting the walls of the container.
What is the relationship between pressure, volume and kinetic energy?
Increasing the pressure means that there are the same number of particles but in a smaller volume. Decreasing the volume will increase the pressure meaning the molecules will collide with the container walls more frequently.
What is diffusion?
Diffusion is when the particles move from an area of high concentration to an area of low concentration until the particles are evenly distributed. Diffusion happens on its own and no energy input is required.
How does relative molecular mass affect diffusion?
Gases with a lower relative molecular mass are lighter which means that they travel faster and further in the same amount of time. Whereas gases with a higher relative molecular mass are heavier which means that they travel slower and not as far in the same amount of time.
