PURE SUBSTANCES AND MIXTURES

INTRODUCTION Hello, today I´m going to talk about: What are pure substances. What is a mixture. The elements of the mixtures that are HETEROGENEOUS and HOMOGENEOUS. Components of a mixture: Magnetism, Filtration, Decantation and Evaporation. Questions and answers

WHAT ARE PURE SUBSTANCES? A pure substance is a substance that cannot be separated by physical means. Some examples of pure substances are water, gold, glucose, carbon dioxide, oxygen and hydrogen.

WHAT IS A MIXTURE? A mixture is made when two or more substances are combined, but they are not combined chemically.  General properties of a mixture: The components of a mixture can be easily separated The components each keep their original properties The proportion of the components is variable

GROUPS OF MIXTURE There are two main categories of mixtures: homogeneous mixtures and heterogeneous mixtures. Then you can see a small diagram of heterogeneous and homogeneous.

HETEROGENEOUS MIXTURE A heterogeneous mixture is one that consists of two or more substances. It is non-uniform and the different components of the mixture can be seen. Some examples of heterogeneous mixtures are: cereals with milk and a salad.

HOMOGENEOUS MIXTURE A homogeneous mixture is one that is uniform, where the different components of the mixture cannot be seen and they have specific properties. . Some examples of homogeneous mixture are: air and solution of salt.

MAGNETISM Magnets are objects that produce an area of magnetic force called a magnetic field. Magnetic fields by themselves are invisible to the human eye. Magnets only attract certain types of metals, other materials such as glass, plastic and wood aren't attracted. .

FILTRATION Filtration is the separation of solid particles in a mixture by passing the mixture through a screen that prevents the big parts from going through while allowing the little particles to go through. You can think of a liquid as very very small particles.

DECANTATION Decantation is a process used to separate a mixture. It usually involves removing the liquid portion of a substance while leaving behind the sediment. Some examples of decantation are: oil and water and red wine.

EVAPORATION Evaporation is the vaporization of a liquid, where a liquid become a vapor. It is the reverse of condensation and allows a liquid to change form to a gas. Some examples of evaporation are: salt and water and water turns to humidity air.

QUESTIONS AND ANSWERS WHAT IS A MIXTURE? A mixture is made when two or more substances are combined, but they are not combined chemically WHAT IS A FILTRATION? Filtration is the separation of solid particles in a mixture by passing the mixture through a screen that prevents the big parts from going through while allowing the little particles to go through.