Without electromagnetism, atoms would not exist, as it is essential for the formation of atomic structures. The absence of nuclei would mean that there would be no stars, leading to a universe composed solely of nucleon dust. This fundamental force is crucial for the stability of matter, impacting everything from chemical reactions to the formation of planets. The implications extend to the absence of light and electricity, fundamentally altering life as we know it. Overall, a world without electromagnetism would be drastically different and devoid of the complex structures we rely on.