Rainwater is fairly pure
however it can also pick up some particulate matter and electrolytes from the
air, although not much. It will be saturated with atmospheric CO2, so with a little
buffering capacity, it will be at a pH of about 5.5, which is also the pH of
carbonic acid, a weak acid. Hence rainwater is a weak acid.
Explanation:
1) Initial mass of the Cesium-137== 180 mg
Mass of Cesium after time t = N
Formula used :
Half life of the cesium-137 = = initial mass of isotope
N = mass of the parent isotope left after the time, (t)
= half life of the isotope
= rate constant
Now put all the given values in this formula, we get
Mass that remains after t years.
Therefore, the parent isotope remain after one half life will be, 100 grams.
2)
t = 70 years
N = 35.73 mg
35.73 mg of cesium-137 will remain after 70 years.
3)
N = 1 mg
t = ?
t = 224.80 years ≈ 225 years
After 225 years only 1 mg of cesium-137 will remain.
Answer:
Potassium-40 (40K) is a radioactive isotope of potassium which has a long half-life of 1.251×109 years. It makes up 0.012% (120 ppm) of the total amount of potassium found in nature.
...
Potassium-40.
General
Natural abundance 0.0117(1)%
Half-life 1.251(3)×109 y
Parent isotopes Primordial
Decay products 40Ca (β−) 40Ar (EC, γ; β+)
Ml=−2,−1,0,+1,+2.
<span>Since each of these orbitals can hold a maximum of </span>two electrons<span>, one having spin-up and one having spin-down, a total of </span>10 electrons<span> can share the quantum numbers n = 4 and l = 2</span>
Answer:
Lead
Explanation:
As you move down the periodic table, the elements get larger and gain additional electron shells, increasing the radius. In order, they are on the table as Chlorine, Selenium, Lead.