How were the elements past iron formed?

When a massive star uses up all of its fuel ending with iron it generates too little heat and pressure to resist gravity and collapses. When all the matter tries to reach the center of gravity (like falling stones?) pressure and temperature are increased enough to fuse existing elements into all the heavier elements with a tremendous release of fusion energy. This creates a supernova explosion leaving behind a neutron star. The implosion results in an explosion.

Yes, you're right. Low-mass and high-mass stars (in their main sequence stage) produce all elements up to iron. However, the heavier elements of gold, lead and others were not formed at that point.

It is when high-mass stars die that the rest of elements are formed. This stage of death in a high-mass stars life is the "supernova": a large explosion that is somewhat like a mini Big Bang.

Elements past Iron are formed in Supernova explosions which can form elements with atomic masses up to 254.

Elements past iron are created in a supernova. The energy to form them comes from the explosion.

Principally by neutron capture processes.

The R-process in supernovae.

The S-process in Asymptotic Giant Branch stars.

Carbon is extra to organic iron to make it steel. the share of carbon content fabric could be between 0.25 to a million.25%. To make chrome steel some nickel and chromium are extra to organic iron.