Is #5 right ? ? i don’t understand net charge.

Net charge is the charge that the element has. Those are often used for forming ions mainly because all of them tend to be balanced.

the cold front replaces the warmer air at the ground level changing the wind to be breezy and denser.there is also an immediate drop in the temperature.

metric time was an attempt to create a standard unit of time based off of 10, but it never took off an is not included in the metric system (si)