During a hard freeze, if there is only water and no antifreeze in the motor of your vehicle: at best, the freeze plugs will burst or pop out; at worst, the block will crack.
it breaks stuf
I believe that STRAIGHT antifreeze , not mixed with preferably distilled water , freezes at 7* Fahrenheit
No. The antifreeze has to be mixed with the water before the water freezes.
Most antifreeze has a chemical that freezes at a very lower temp than plain water.
As the water freezes, it will expand.
If you mean the water in your radiator, don't drive your vehicle until it thaws or your engine will overheat because no coolant will be flowing through it. You should keep 50% antifreeze and 50% distilled water in your car radiator at all times. (maybe slightly more antifreeze in cold winter weather) Water in the radiator won't freeze with antifreeze mixed with it.
it remain the same as it has definite volume.
If it freezes just a little it becomes cold water, but if it freezes more it becomes ice.
Water freezes.
Increases.
You dilute your antifreeze. If you buy prediluted 50/50 antifreeze, then you'll dilute it more than you're supposed to. If you buy straight 100% antifreeze, you're actually supposed to dilute it yourself by adding an equal amount of water to the antifreeze you put it. Your vehicle will be fine. Stop freaking out. Get a coolant flush.
it gets cold and freezes