Ionic and covalent bonds have different properties because of how their atoms are built and how they stick together. Let's break it down:

Ionic Bonds:

• Ionic bonds happen when positive and negative ions attract each other.
• They usually form between metals and nonmetals, creating solid structures called crystals.
• Materials with ionic bonds often have high melting and boiling points. A common example is table salt (sodium chloride, or NaCl).
• Ionic compounds typically dissolve well in water and can conduct electricity when they're either dissolved or melted. This is because the ions can move around freely.
• However, ionic compounds can be brittle. This means if you hit them or apply pressure, they can break. This happens because their structure is rigid, and when they shift, like charges align and push away from each other.

Covalent Bonds:

• Covalent bonds occur when two atoms share electrons. This usually happens between nonmetals.
• These bonds can create many different kinds of structures. For example, water (H2O) is a simple molecule, while diamond is a complex network.
• Generally, materials with covalent bonds have lower melting and boiling points than ionic compounds. But some, like diamond, are exceptions and can be very hard.
• Covalent compounds usually do not conduct electricity well because they lack charged particles that can move. However, some structures, like graphite, can conduct electricity due to electrons that move freely.
• Covalent compounds can also be more flexible, depending on how the atoms are connected.

Summary:

In short, ionic bonds make hard and brittle materials with high melting points, while covalent bonds offer more flexibility and variety in material properties. Knowing the differences between these two types of bonds is important when choosing materials for engineering and technology.