Standards
SC.912.P.8.7: Interpret formula representations of molecules and compounds in terms of composition and structure.
Matter
All matter in the known universe is made of atoms and their smaller components. Each square in the periodic table represents an element
- Each element consists of a single type of atom
- Atom – the smallest unit of a chemical element
- The 3 components of an atom are;
- Protons- Has a positive electric charge
- Neutrons- Has no electrical charge (is neutral)
- Electrons- Has a negative electric charge. Is the smallest part of an atom.
What makes different materials so different from each other?
- Materials and substances are different from one another because they contain different elements (types of atoms)
- Different types of atoms (different elements) have different numbers of subatomic particles (Protons, Neutrons, and Electrons)
| Element | Proton(s) | Neutron(s) | Electron(s) |
| Gold | 79 | 118 | 79 |
| Iron | 26 | 30 | 26 |
Atoms can bond together to form larger structures called “molecules”
- Molecule – a group of atoms (2 or more) that are bonded, or stuck, together
- Atoms will “share” electrons with each other and be bonded together as a result
- Atoms that are bonded make up molecules, and molecules make up materials and substances
Water molecules are too small to be seen by the naked eye, but when many water molecules are together water becomes visible
pH- Acidity vs Alkalinity
pH – a scale used to specify the acidity or basicity of a solution.
*Technically the pH scales measures the amount of protons. Acids have more protons while bases have fewer protons
- As you go up in pH the pH changes by a factor of 10!
- For example, A chemical with a pH of 3 is 10 times more acidic than something with a pH of 4!
States of matter
The atoms that make up any material are in a constant state of motion, the more energy this material contains the faster the atoms move while the less energy it contains means the atoms move slower. We can measure this movement as “Kinetic Energy” or what we commonly refer to as “Temperature“.
- Solids- state of matter in which the atoms are very closest together, because of this the atoms do not vibrate as much as the other states. Atoms in this state don’t tend to move past each other as much. Matter in this states tends to be hard and rigid.
- Liquids- state of matter in which the atoms are farther apart than solids. Atoms in this state can move past each other much easier than solids, this causes liquids to take on the shape of their containers.
- Gasses- atoms in this state move the fastest and vibrate with the most energy. The atoms of gasses move past each other freely and even bounce off one another.
Solutions
In our everyday lives we often have to mix solids and liquids. We often dissolve solid food materials like powders into some type of liquid like milk or water. When we are dissolving solids in liquids we are creating a new mixture of materials, this mixture is called a “solution”. If you are preparing chocolate milk the solid (solute) is dissolved in the milk (solvent), this creates a new mixture called chocolate milk (solution).
- Solute – substance getting dissolved (it can be sugar,salt,or any chemical)
- Solvent -substance doing the dissolving (a liquid of some kind like water)
- Solution – The mixture or combination of both a solute suspended in a solvent
