<span>The troposphere is the lowest portion of Earth's atmosphere. It contains approximately 75% of the atmosphere's mass and 99% of its water vapour and aerosols. The average depth of the troposphere is approximately 17 km in the middle latitudes. It is deeper in the tropics, up to 20 km, and shallower near the polar regions, approximately 7 km in winter. The lowest part of the troposphere, where friction with the Earth's surface influences air flow, is the planetary boundary layer. This layer is typically a few hundred meters to 2 km deep depending on the landform and time of day. The border between the troposphere and stratosphere, called the tropopause, is a temperature inversion.</span>
The health effects of drinking contaminated water can range from no physical impact to severe illness or even death. Some of the effects of drinking contaminated water can be immediate, or not noticed for many years. These include gastrointestinal and stomach illnesses like: nausea.
Answer: 14.14 billion years (which is close to the age of the universe)
Explanation:half life (t1/2) U-235 = 703.8*10^6
original amountN0 at time t Nt = NO/4
t= (t1/2)*(ln(Nt/N0)/-ln2
= (703.8*10^6)*(ln0.25)/-ln2
= (703.8*10^6)*(-1.386)/-0.69
= 14.14*10^9 years