Which of the following elements is found in both carbohydrates and water?

• A. helium
• B. oxygen
• C. carbon
• D. nitrogen

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the composition of carbohydrates. Carbohydrates are organic molecules made up of carbon (C), hydrogen (H), and oxygen (O) atoms, typically in a ratio close to 1:2:1.
2. Step 2: Understand the composition of water. Water is a simple molecule composed of hydrogen (H) and oxygen (O) atoms, with the chemical formula \(\mathrm{H_2O}\).
3. Step 3: Compare the elements present in carbohydrates and water. Carbohydrates contain carbon, hydrogen, and oxygen, while water contains hydrogen and oxygen.
4. Step 4: Identify the common element(s) between carbohydrates and water by looking at the overlap in their elemental composition.
5. Step 5: Conclude that oxygen is the element found in both carbohydrates and water, as it is present in the molecular structure of both substances.