Scientific Tutor

What are the different types of solids?

VIDEO explanation of the Different Types of Solids.

Depending on the book and teacher you have they might describe the names of the different types of solids in a slightly different way. Keep in mind the names I describe here are the most common ones I have heard. The table below has the different types of solids.

The first 4 types of solids (metallic, ionic, molecular, and Network Covalent) are all referred to as crystals because they have a very organized and repeating structure. The last type, amorphous is not a crystal because it does not have a repeating chemical structure. Mostly what confuses people on this section of chemistry is determining which types of solid a particular chemical is. Lets look at an example below:

Example: NH₃ will form what type of solid?

Answer: Molecular

HOW THE HECK DID YOU GET THAT ANSWER? Good question. It goes back to a lot a material we have learn previously but especially focusing on the sections of covalent and ionic bonds and the Lewis Structures lesson up to completing the octet. I GUARANTEE YOU IF YOU DO NOT UNDERSTAND THESE PREVIOUS SECTIONS YOU WILL NOT UNDERSTAND ANYTHING I AM ABOUT TO WRITE BELOW.

The question to keep in mind during this section is what are the weakest possible bonds that form in each chemical compound? If you can identify those bonds or forces then you will be able to answer the practice problems below and the questions you will have on your test. Below is another table about how I want you to think as you are going through the problems.

Metallic: Any chemical that contains just metals will contain only metallic bonds. Examples: Al₂Mn₃, Na2Zn, Cu₂Pb

Ionic: Any compound that contains a least one metal and at least one non-metal contains only ionic bonds. Examples: KBr, FeCl₃ , MgF₂

Molecular: Will only contain non-metal elements and therefore have covalent bonds but these are not the only types of bonds they contain. Their weakest bonds will be Hydrogen, Dipole-Dipole, or London-Dispersion. Under extreme cold temperatures and high pressures these can form solids. How is it best to distinguish these from Network Covalent solids? Molecular solids can be drawn as a Lewis Structure but Network Covalent cannot. Examples: NH₃, H₂S, CO₂ (dry ice)

Network Covalent: Will have only non-metals and therefore contain covalent bonds. Unlike the molecular you will not be able to draw these as a Lewis Structure (only exception is SiO₂). Examples: C₄ (diamond), S₈, PN₃

Amorphous: This category could include anything because it is not dependent on what elements are in it. Amorphous (without form) is only dependent on how the elements are arranged relative to each other. They can have no repeating pattern only a disorganized mix. Examples: Soil (dirt), rubber, plastic

PRACTICE PROBLEMS: Name the type of solid for each chemical below. Your options are metallic, ionic, molecular, or covalent network. Amorphous will not be used in these practice problems.