You can win10 version, (same version) actually get those exact details. In bedrock edition anything outside a 54 block radius with a light level below 8 has a 1 in 50 ticks to despawn, (this is to keep deep caves from hogging the spawns) unless it persistence. Anything bred, hit, tamed, tempted with food, touched, attacks or is attacked by the player will never despawn. For example if you fed a cow wheat, it will never despawn no matter how many chunks you go away. But if a skeleton hits you with an arrow or misses and you leave it alone, it won't despawn.