Answer:

Explanation:
An element only has <u>one</u> type of atom and cannot be broken down by chemical means.
Let's analyze the answer choices.
1. This has two types of atoms, so it cannot be an element. It has more than one type of atom.
2. This has two types of atoms that are bonded together. It cannot be an element because there is more than one type of atom and the bonds can be broken.
3. This has one type of atoms, so it is an element.
Therefore the best answer choice is 3.
The folds in the photograph above were caused by compression at a thrust fault or a convergent plate boundary. Compression usually occurs where two tectonic plates converge or collide. The compression will cause rocks to fold upwards and this upward folding over time can lead to the formation of extensive fold mountains. Examples of fold mountains include the Alps, Andes, and the Himalayas.
Phagocytosis is the answer to this one :)
Punctuated equilibrium, it is rapid evolution with little change in between
Subsets of {dog, cat, fish} are Ф, {dog}, {cat}, {fish}, {dog, cat}, {dog, fish}, {cat, fish}, {dog, cat, fish}.