Which of the following elements exists as a diatomic molecule in its standard elemental form?

• A. Oxygen
• B. Neon
• C. Sulfur
• D. Phosphorus

Answer: (A)

Verified step by step guidance

1. Understand that some elements naturally exist as molecules composed of two atoms (diatomic molecules) in their standard elemental form, rather than as single atoms or larger molecules.
2. Recall the common diatomic elements, often remembered by the mnemonic 'BrINClHOF', which stands for Bromine (Br2), Iodine (I2), Nitrogen (N2), Chlorine (Cl2), Hydrogen (H2), Oxygen (O2), and Fluorine (F2).
3. Analyze each option: Neon is a noble gas and exists as single atoms (monatomic), Sulfur typically exists as S8 molecules (octatomic), Phosphorus commonly exists as P4 molecules (tetra-atomic), and Oxygen exists as O2 molecules (diatomic).
4. Identify that among the given options, Oxygen is the element that naturally exists as a diatomic molecule (O2) in its standard elemental form.
5. Conclude that the correct answer is Oxygen because it is one of the seven diatomic elements that exist as molecules of two atoms under standard conditions.