The crackling sound Is mainly to do with chemistry, The fireworks are filled with lead oxide, which turns into lead atoms as the firework explodes and heat up—— whistling sounds, the whistle is down to the tube being narrow one, thus rockets make a whistling noise
The equation for determining the energy of a photon of electromagnetic radiation<span> is #E=hnu# , where E is energy in Joules, h is Planck's constant, #6.626 xx 10^(-34)J*s# , and #nu# (pronounced "nu") is the frequency
hope this helps</span>
A nucleotide is composed of a phosphate group, sugar, and nitrogen base. DNA is made of 2 strands of nucleotides linked together by covalent bonds between the phosphate and sugar of each nucleotide. The strands of nucleotides are linked together by hydrogen bonds creating DNA. Hope this helps and sorry if I made a mistake.