Is it better for the environment to throw and apple core outside?

It does help the environment but you might have to dig a hole in the ground and put the apple core in it then put the dirt back on top. This will help in providing the soil nutrients and it decomposes faster. It depends if you want to plant things in the front or back of your house, anywhere you throw it, there will be more nutrients and whatever you plant will grow better.

It helps to compost it. You won't use the gas to truck your garbage to a landfill, it will release it's nutrients and nitrogen into the soil, and it will use less space in your garbage bin.

In my city, around 40% of the homes compost. Many don't have backyards that are large enough for a compost pile, or they simply are too lazy to dig and bury the food scraps. If you have a compost/yard waste bin that is picked up frequently, please utilize it, by tossing food scraps, paper plates, napkins, pizza boxes, bones, and plant trimmings.

yes, it's also used to make plants grow better. Composting it gets you expensive soil.

Yes a squirrel might eat it too.

yes. it acts as compost for the earth

yes

Give it to the hens/wildbirds/dog. They all love them and there will be no wastage.