Here's why:

* Density: Specific gravity is a measure of the density of a substance relative to the density of water.

* Atomic Structure: Metals typically have tightly packed atoms in a crystalline structure, leading to high densities.

* Exceptions: There are some exceptions to this rule, like alkali metals like lithium and sodium, which have relatively low densities.

Examples of Metals with High Specific Gravity:

* Gold: 19.3 g/cm³

* Lead: 11.3 g/cm³

* Iron: 7.87 g/cm³

* Mercury: 13.5 g/cm³ (liquid metal)

Let me know if you have any other questions!