Denver's atmospheric pressure is 83.4 kPa, boiling temperature is 94.59°C. Water in 2.5 m³ tank at 75°C becomes completely vaporized at 140.7°C. Water at 0.5 MPa pressure and 2890 kJ/kg enthalpy reaches 240°C
Airships are powered, dirigible aircraft using buoyancy from lighter-than-air gases. Early hydrogen airships were flammable, later replaced by non-flammable helium. Modern airships can lift 3,000 pounds to 4.5 km altitude
2 is the smallest and only even prime number. All multiples of 2 end in 0, 2, 4, 6, or 8. It is the first Ramanujan prime and superior highly composite number
Blimps are still flown despite the Hindenburg accident. There are fewer than 50 blimps worldwide. Blimps combine balloon and aeroplane features. They are the most highly-developed heavier-than-air flying machine
Thermal conductivity varies with temperature and pressure for most materials. Most materials are nearly homogeneous, so k = k(T) applies. Thermal conductivity increases with temperature difference and conductivity
Lewis Dot Structure shows valence electrons as dots in element symbols. Maximum of eight electrons can be represented. Helium has two valence electrons in its first orbit. Electrons are represented as lone pair dots in Lewis symbol