Natural Sciences Grade 7 Term 2 Matter Materials

Natural Sciences Grade 7 Term 2: Matter & Materials Separating mixtures (ppt 1)

Topic 2 Separating mixtures Mixtures Natural Sciences - Grade 7

Mixtures [substances] Examples of pure substances: • Gold particles • Gold nuggets • Water particles (all the particles in a glass of water are the same). • Table salt particles (all the particles in a spoon of table salt are arranged the same way) Natural Sciences - Grade 7

Mixtures [particles] Natural Sciences - Grade 7

Mixtures [examples] A mixture is made up of 2 or more materials or Substances, which have different physical properties. Sea water mixture of water and salt; Brass mixture of zinc and copper; Air mixture of gases [oxygen; nitrogen; carbon dioxide] Concrete mixture of cement, water, sand lime. Natural Sciences - Grade 7

Mixtures [solutions] • A mixture of a solid dissolved in a liquid is called a solution. Natural Sciences - Grade 7

Mixtures [physical properties] The parts of a mixture have different physical properties: • The substances of beans and rice, as well as fruit salad that are mixed, keep all of their own physical properties. • Different mixture parts do not join together, but it can be combined in any amounts. Natural Sciences - Grade 7

Mixtures [examples] Natural Sciences - Grade 7

Mixtures [combination of properties] • The particles of one substance move in between the particles of the other substance when the two are mixed. • Salt water looks like water, but it tastes like salt (It is a combination of the properties of the substances that are mixed). Natural Sciences - Grade 7