Basic/starter info (: substances,
molecules, mixtures, PH, etc).
Table of contents.
Properties of substances.
Scientific notations and units.
Transition of phases.
Types of mixtures.
PH and acidity.
Properties of substances.
Everything around us is made up of materials. A material is a substance or mixture of
substances that constitutes (make/build) an object.
A pure substance is only one substance.
Mixtures consist of two or more substances.
→Air is a mixture, consisting mostly of nitrogen and oxygen.
→Sugar is a pure substance.
The chemical process of changing a substance into another substance is a chemical reaction.
The characteristics of a substance are the properties of a substance, this defines them.
→Eg. colour, taste, solubility, flammability, density, phase at room temperature,
melting & boiling point, etc.
Physical quantaties are properties that you can measure. (Mass, volume, etc.)
This does NOT define a substance, so it’s not a property of a substance.
The unit is the size with which you measure a quantity.
→Eg. kilogram for mass, litre for volume, and more.
The combination of mass and volume equals the density.
Basic/starter info (: substances, molecules, mixtures, PH, etc). 1
, Density can determine what material and object is made of.
To calculate density, you divide the mass by the volume (density = mass/volume).
→Eg. of units that can be used: kg/m³ or g/mL.
Scientific notations and units.
Kilo (K) is a prefix meaning a thousand (1 Km = 1000 m) →10³
Milli (m) means one thousandth (1 mm = 0.001 m) →10⁻³
Mega (M) means a million (1 Mm = 1,000,000 m) →10⁶
When converting units (M→K) you often use scientific notations.
This is written in powers of 10.
→5000 = 5 * 10 * 10 * 10 = 5 * 10³
Transition of phases.
Almost every substance can occur in three states of matter (phases).
1. Liquid (l).
Substance is at a temperature between its melting point and boiling point.
2. Solid (s).
Substance’s temperature is below its melting point.
3. Gas (g).
Basic/starter info (: substances, molecules, mixtures, PH, etc). 2