Q MULTIPLE CHOICE Question 3 Why are metals good conductors of heat and electricity? A The metal's valence electrons move freely through the metal. B The metal's valence electrons move to higher energy levels. C The metal's valence electrons are stationary. D The metal's valence electrons vibrate in place.

## Step 1<br />Metals are good conductors of heat and electricity due to the behavior of their valence electrons. Valence electrons are the electrons in the outermost shell of an atom that are involved in forming bonds with other atoms.<br /><br />## Step 2<br />In metals, these valence electrons are not tightly bound to their parent atoms. Instead, they are free to move throughout the metal. This movement of electrons is what allows metals to conduct electricity and heat.<br /><br />## Step 3<br />When an electric potential difference (voltage) is applied across a metal, these free electrons move towards the positive terminal, creating an electric current. Similarly, when heat is applied to a metal, these free electrons can transfer kinetic energy from the hotter region to the cooler region of the metal, facilitating the transfer of heat.<br /><br />## Step 4<br />Option B, "The metal's valence electrons move to higher energy levels," is not directly related to the conduction of heat and electricity. While electrons can move to higher energy levels when energy is supplied (like in the case of heating), this is not the primary reason metals are good conductors.<br /><br />## Step 5<br />Option C, "The metal's valence electrons are stationary," is incorrect because stationary electrons would not contribute to the conduction of heat or electricity.<br /><br />## Step 6<br />Option D, "The metal's valence electrons vibrate in place," is also incorrect. While it's true that atoms in a metal vibrate due to thermal energy, this is not the primary reason metals are good conductors. The ability of metals to conduct heat and electricity is primarily due to the free movement of their valence electrons, as stated in Option A.