<span>After 1 half-life, 1/2 the sample has decayed. After 2 half-lives 3/4 of the matter has decayed. So after, 3 half-lives about 11/12 would have decayed.</span>
Answer:
It is a chemical change.
Explanation:
When the electricity is off, the filament cools down to its original physical state. This physical process repeats every time the light is turned on and off. However, if the bulb is cracked and air is introduced, the oxygen in the air reacts with the tungsten filament which then undergoes a chemical change.
Answer:
Barium precipitation : in this method we will add Barium chloride to the wastewater to precipitate Barium sulphate precipitate from the waste water
Explanation:
The measures that can be taken for the recovery of sulfates and other contaminants from wastewater includes : ion exchange, precipitation and Reverse osmosis. of all these measures i will discuss precipitation
Precipitation measures can be performed using different methodologies the methodology that i will discuss is :
Barium precipitation : in this method we will add Barium chloride to the wastewater to precipitate Barium sulphate precipitate from the waste water
The sulphate contained in the wastewater can be reduced to as low as 200 mg/l using this method
Temperature : the increase in temperature of the waste water will cause the reduction in formation of sulphate in the waste water
PH changes : for the precipitation of sulphate to be effective the required PH level is 4.5
