What is the name of the positively charge particle found in the nucleus or center of an atom?

The loss of energy as it is transferred from one trophic level to the next higher level is an example of 

In biogeochemical cycles the word fixation refers to changing matter/atoms 

Which biogeochemical cycle is a slow cycle because the element is not found in gas form and because the main source is in rock formations, which take a long to make and to break down?

What is one reason that a certain percentage of land was preserved on islands such as Mauritius and Tobago during the 1700s when they were English and French colonies?

Describe one reason that someone may oppose the sustainability ideas of Agenda 21.

The type of system in which energy and matter can enter and exit is called a(n) _____ system.

Which of the following key factors of Agenda 21 is considered to be the central idea that if solved could also solve other issues addressed by the Agenda?

A population is defined as 

Which of the following is an example of a producer?