A certain capacitor connected in series with a resistor is being charged. At the end of 2.0 x 10-3 s its charge is 1/2 of the maximum value. What is the approximate value of the time constant of the RC circuit

The earth has changed slot because people built houses,stores, business, buildings,and slot of other stuff. Also we have been pulluting our earth,thinking that people will clean it up for us. Since we all think this,our earth is getting dirty and gross. Before, none of this was happening,no people thinking others would clean it up, or no buildings, house's,stores or anything