What is the smallest unit of an element that still can be identified as a specific element

The health, management and conservation of biodiversity, is a challenge facing ecosystems worldwide. the major factors that affect the health and function of the great barrier reef are climate change and pollution. which question investigates the effects of a biotic factor on the reef ecosystem?

What did hunter gathers do to alter the environment?

There are fewer than 100 naturally occurring elements in the universe, but there are millions of different unified substances. explain how this can be true.