Answer:
six noble gases
Here are five of the six noble gases: helium, neon, argon, kypton and xeon. They're all colourless and transparent. Krypton and xeon form compounds only with difficulty. Helium, neon and argon don't form compounds at all.
Answer: 10.3 mol/l
Explanation: Molality = concentration c = n/V
Amount of substance n = m/M = 150 g / 58.44 g/mol =
2,5667 mol . c = 2.5667 mol / 0.25 l = 10.2669 mol/l
c =
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+)
B............................
The answer is that they are a source of clean energy. This is because the renewable resources do not produce environmentally hazardous emissions during the production of energy.