Natural Science CLEP Prep Practice Exam

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Prepare for the CLEP Natural Science Exam with our comprehensive study materials and practice questions. Test your knowledge and ace the exam by mastering key concepts.

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What element is present in all organic molecules?

Carbon
Hydrogen
Oxygen
Nitrogen

The correct answer is: Carbon

Carbon is present in all organic molecules because it is able to form strong bonds with many other atoms, including itself. This allows for the formation of complex and diverse molecules necessary for life. While hydrogen, oxygen, and nitrogen are also common in organic molecules, they are not present in all of them. For example, many carbohydrates have the formula (CH2O)n, and do not contain nitrogen. Oxygen is also not found in all organic molecules, as some may only contain carbon and hydrogen, such as oils and waxes. Nitrogen is essential for life, but is not the defining element of organic molecules. Therefore, A is the only correct answer.