Question

Water, H2O, is made up of different elements, hydrogen and oxygen. Is this type of combination a mixture or a pure substance? A) Because water is composed of two separate elements, it is a mixture. B) Because water can be heated and fairly easily turned to steam, it is a mixture. C) Because water is composed of elements found in the periodic table, it is a pure substance. D) Because water molecules all have a consistent ratio of hydrogen to oxygen, it is a pure substance. E

Answer 1

the correct answer is D i just got it on USATestPrep. Your welcome.

Answer 2

A pure substance is a substance with a consistent ration of the elements that make it up. This means that there is no way to tell one water molecule apart from the other. The atoms in a pure compound contain atoms bonded in the same way throughout the compound.

On the other hand, a mixture  has constituents that have different pure substances mixed together. The constituents of a mixture are easy to distinguish from each other.

With these definitions in mind, we can easily see that water is a pure sustenance because water molecules all have a consistent ratio of hydrogen to oxygen atoms.

The correct answer for this question is D)Because water molecules all have a consistent ratio of hydrogen to oxygen, it is a pure substance.