My understanding is they can spawn no closer than 16 blocks from you, and I believe up to 125 away outside of that 16 in any direction, up, down, left, right, forward, and back.
Chat with our AI personalities
No, mobs will not spawn in water or ontop of half slabs.
In Minecraft Classic, mobs can't spawn, so they can't exist naturally. If you play the Survival Test, and when mobs spawn there, you can save it and open it in creative mode so then the mobs can stay there. However, in Minecraft Creative Mode, mobs can spawn, but they can't hurt you because you have no healthbar.
No, the AI for mobs in minecraft has been improved so mobs don't spawn in strange places. You can manually spawn them in lava with that mob's egg.
The only mob that can spawn in water is currently a squid.
Yes, in the Nether Zombie Pigmen spawn on the netherrack but I don't think they spawn on Netherrack in the Overworld.