how much is ielectricity usually for a one bedroom apartment?

Answer 1

To help yourself answer that question, think about things like:
The sun rises and sets east & west. If your windows are on these sides, it will take more to keep cool, "will benefit you in the winter months though". Do you have electric dish washer, stove, water heater, etc? Are you alone meaning 2 showers a day or 4. All these things will play apart in your billing.

Answer 2

depends on wher you live and about 50 other factors we do not know about