Question

A molecule of DNA (deoxyribonucleic acid) is 2.29 µm long. The ends of the molecule become singly ionized: negative on one end, positive on the other. The helical molecule acts like a spring and compresses 1.16% upon becoming charged. Determine the effective spring constant of the molecule.

I gave the answer 1.6539e-9 N/m , but it was wrong and this is the response it gave me:
Your response is within 10% of the correct value. This may be due to roundoff error, or you could have a mistake in your calculation. Carry out all intermediate results to at least four-digit accuracy to minimize roundoff error. N/m

Answer 1

if the force between ions on either ends of the DNA molecule F the seperation between eithe ends after compression (1-1 . I 6%) x 2.29μm r 2 r-2.263e-06 m 2 -2 coloumb constantc-8,98x 10 N.mt .c we plug the values in hand, while using the relation F 4.503e-017N if the spring forceconstant of DNA is and DNA compressed distance (1 . I 6%) x 2.29 um-0.02656 um Дж > F-k/X ; we plug the values in hand while using the relation give us 1.695e-09