Unit Conversion: Joules to Microjoules

Steps:

• Know that 1 J = 10^6 μJ, since micro means 10^{-6}.
• Multiply 4.3 J by 10^6 to convert: 4.3 × 10^6 μJ.
• Verify the exponent: positive 6 scales up from J to μJ.
• Match to choices: this equals option A.

Why A is correct:

• By definition, 1 J = 10^6 μJ, so 4.3 J = 4.3 × 10^6 μJ exactly.

Why the others are wrong:

• B: Uses 10^{-6}, which divides by 10^6, yielding 4.3 μJ, far smaller than 4.3 J.
• C: 10^{-3} is even smaller (millijoules scale), not matching microjoules conversion.
• D: Remains in J but scaled down to 4.3 μJ, not equivalent to original 4.3 J.

Final answer: A