Answer is: A.
1. Metallic bond is a type of chemical bond.
2. Metallic bond is formed between electrons and positively charged metal ions.
3. Metallic radius is defined as one-half of the distance between the two adjacent metal ions.
4. Metallic bond increace electrical and thermal conductivity.
5. Metals conduct heat, because when free moving electrons gain energy (heat) they vibrate more quickly and can move around.
