Organization of matter

Introduction

Matter is the name that we give to everything physical in our universe. Everything that could be detected by some kind of instrument. Matter is what makes up everything that is around us: the air, the water, the chair you sit on, the laptop you use. It is not necessarily visible by the naked eye, but scientific instruments can detect it.

Dark matter, is what we cannot detect necessarily. It is a very abstract concept difficult to explain and from what physicists know (which is not a lot) it’s everywhere. We know it exists because of the traces it leaves behind, but scientific instrument cannot detect because it is not made up of matter. Think of it this way: if you see footprints in the sand. Do you need to see the person to know that someone was there? It is similar with anti-matter. We see its footprints but we don’t know what left it there.

Matter can be organized as follows. Please note that there are further subdivisions, but these are the ones that we will discuss in your grade 9 science class.

From smallest to biggest:

• Subatomic particles (protons, neutrons and electrons)
• Atoms (Hydrogen, Helium, Carbon, Oxygen, etc.)
• Molecules (Carbon dioxide, H2O, etc.)
• Macromolecules (Starch, proteins, lipids)
• Organelles (mitochondrion, nucleus, golgi apparatus, etc.)
• Cells (neurons, muscles cells, liver cells, -cytes, etc.)
• Organs (heart, brain, liver, kidneys, etc.)
• Organ systems (respiratory system, cardiovascular system, nervous system, etc.)
• Organism (human, mouse, cat, dog, etc.)

The green ones, we will look at later on in the living world unit. The ones written in black, we will look at in more detail below.