SECTION A - Principle Of Chemistry Flashcards
(17 cards)
Explain how evidence supports the particulate theory of matter
The Particle Theory of Matter helps us think about how matter behaves. It can be used to explain why matter exists in different phases (solid, liquid, and gas), as well as how matter can change from one phase to the next.
The main ideas of the particulate theory of matter:
- All matter is composed of particles.
- The particles are in constant motion and temperature affects their speed of motion.
- The particles have empty spaces between them.
- The particles have forces of attraction between them
The following processes provide evidence for the particulate theory of matter:
- Diffusion
- Osmosis
- Brownian Motion
Define Brownian motion
The random motion of particles suspended in a fluid resulting from their collision with the fast-moving atoms or molecules in the fluid.
Define Matter
Anything that has volume and mass
When is a heating curve drawn?
A heating curve is drawn when the temperature of a solid is measured at intervals as it is heated and changes state to a liquid and then to a gas, and the temperature is then plotted against time.
When is a cooling curve drawn?
A cooling curve is drawn when the temperature of a gas is measured at intervals as it is cooled and changes state to a liquid and then to a solid, and the temperature is then plotted against time.
What are pure subsances?
Pure substances are made up of only one kind of particle and have a fixed or constant structure.
Characteristics of pure substances:
- Its composition is fixed and constant.
- Its properties are fixed and contrast
- The component parts cannot be separated by any physical process.
Pure substances are further classified as
elements and compounds
What is an element?
An element is a substance that consists of only one type or kind of atom.
Why is an element considered pure?
An element is a pure substance as it cannot be broken down or transformed into a new substance even by using some physical or chemical means.
What are molecules?
A group of atoms bonded together.
What are Compounds?
Pure substances when two or more elements are combined chemically in a fixed ratio. However, these substances can be broken down into separate elements by chemical methods.
Why are Compounds Considered Pure?
There is no physical change that can separate the compounds into more than one kind of substance. This makes a compound a pure substance.
What are mixtures?
A mixture consists of two or more substances (elements and or compounds) which are physically combined together in variable proportions. Each component retains its own individual properties and is not chemically bonded to any other components of the mixture.
