Which statements describe an element? check all that apply.
an element is a pure substance.
an element is made of only one type of atom.
an element is made of two or more different types of atoms.
an element can be broken down into a simpler form.
an element cannot be broken down into a simpler form.

Identify the type of chemical reaction involved in each action.

What causes the cyclical changes in the appearance of the moon?

70 pts answer the following questions in full sentences and paragraphs, using at least 150 words, in the essay box below. 1. which organisms are carnivores? herbivores? omnivores? 2. if the ecosystem is balanced, which populations should be the largest? the smallest? 3. imagine a group of hunters kills half of the rabbit population. how will the other organisms be affected? 4. imagine disease kills 85 percent of the wolf population. how will the other organisms be affected? 5. imagine a foreign mountain lion species is introduced into the ecosystem. how will the other organisms be affected?