Gravitational Potential Energy is the energy associated with

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.

ok yes, but what is the question? as soon as you ask the actual question i will answer it. : )

the alkaline earth metals (beryllium (be), magnesium (mg), calcium (ca), strontium (sr), barium (ba), and radium (ra)) are a group of chemical elements in the s-block of the periodic table with very similar properties: shiny. silvery-white. hopefully this ? i didn't fully understand the question