This week we have started studying the classification of matter:

A Pure substance is made up of only one substance and a Mixture is made up of more than one substance. Pure substances can be Elements or Compounds, an Element is the simplest form of matter (oxigen or hidrogen) and a Compound is a combination of two or more elements (salt or sugar). Mixtures can be Homogeneous mixtures or Heterogeneous mixtures, a Homogeneous mixture is a mixture that you cannot distiguish the different substances but in a Heterogeneous mixture you can distinguish the different substances. A example of a Homogeneous mixture is a solution (vinegar), where you find a solute and a solvent. And two examples of a Heterogeneous mixture are Suspensions (mustard) and Colloids (mayonnaise). You distinguish the solution, the suspension and the colloid because of the size of its molecules: solutions have tiny molecules, colloids have medium molecules and suspensions have giant molecules.

In this topic we also have studied the salt:

Common salt is also known as Sodium Chloride. Its chemical formula is Nacl because Sodium is Na and Chlorine is Cl. When you put some salt into water, the +Na and the -Cl part of the salt are separated, the +Na join with a negative atom of water and the -Cl join with a positive atom of water.

Judith Llobera Ribera