Why are matorials such as glass and rubber good insulators? Electrons are tightly bound to their atoms, making them poor conductors of heat. Electrons are tightly bound to their atoms, making them good conductors of heat. Electrons are loosely bound to their atoms, making them poor conductors of heat. Electrons are loosely bound to their atoms, making them good conductors of heat.

## Step 1<br />The ability of a material to conduct or insulate heat is determined by the behavior of its electrons. In good conductors of heat, such as metals, the electrons are loosely bound to their atoms and can move freely. This allows them to transfer heat energy quickly.<br /><br />## Step 2<br />On the other hand, in good insulators, such as glass and rubber, the electrons are tightly bound to their atoms. This means they cannot move freely, which makes it difficult for them to transfer heat energy.<br /><br />## Step 3<br />Therefore, the statement "Electrons are tightly bound to their atoms, making them poor conductors of heat" is the correct answer. This is because the tight binding of electrons to their atoms in insulators makes it difficult for them to transfer heat energy, which is the characteristic of a good insulator.