If you do not have enough iron many things could happen. You could become anemic as well as extremely fatigued.
It will just melt into the sun, not big enough to make it instantly go supernova.
The iron bar would become more magnetic.
The iron would bubble and flammable gas would be released
it becomes straight
Since iron is a more active metal than copper, the iron would replace the copper in the copper sulfate, forming iron sulfate, and releasing elemental copper. The copper will not shape itself into a copper vessel, so eventually, the iron sulfate would leak out of the iron vessel, and eventually, if there is enough copper sulfate, the iron vessel will cease to exist.
You would develop iron defficency
Nothing.
Rust and be heavy.
You would burn and feel immense pain. Liquid iron is very hot.
your molecules would get bigger since it wouldn't be weighed down by the iron and you would explode into a million pieces
you would die