It depends on whether there is a rooster around to fertilize the eggs. Broiler hens lay eggs that can grow into chicks just as typical egg-layers do - otherwise we wouldn't have broiler chicks to raise.
No, they are unfertilised.
Yes.
sit on the eggs
I think it would be very unusual and rare, because a hen's first egg is usually deformed and small.
Only hens that have a rooster amongst the flock will have been fertilized. Store bought eggs are not fertilized as the mass produced egg suppliers do not allow roosters near the hens. Usually only small farms will sell eggs that may have been fertilized.
a hen can still lay fertilized eggs up to 30 days after contact with a rooster
They eggs will be fertilized about a week after the rooster consistantly starts to mount the female.
Eggs are fertilized inside the hen by the rooster. Hens will lay eggs whether they are fertilized or not.
A fertilized egg that is growing into a chick, after the hen has laid the egg, requires a warm and dry environment for a few weeks to incubate. Man-made incubators are built to incubate over 200 eggs at a time (bigger incubators can hold more), or a nest of straw, grasses and feathers built by a hen are also sufficient, provided the hen is sitting on her eggs as much as she can.
It can be,sometimes you will see blood patches in fertilized eggs.
No, for example human eggs are fertilized internally, as well as many other animals.
The hen will continue to lay fertilized eggs for up to 10 days after the last mating.
no that is how people eat eggs. we eat eggs that chickens/hens hatch that aren't fertilized.