Search results
Results From The WOW.Com Content Network
Why is the Sun's corona so much hotter than the Sun's surface? (more unsolved problems in astronomy) The temperature of the photosphere is approximately 6,000 K, whereas the temperature of the corona reaches 1,000,000–2,000,000 K. The high temperature of the corona shows that it is heated by something other than direct heat conduction from the photosphere. It is thought that the energy ...
As of 2023, by mole fraction (i.e., by number of molecules), dry air contains 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor , on average around 1% at sea level, and 0.4% over the entire atmosphere.
15% ( +10% in profits exceeding BR$ 20.000 + 9% Social Contribution Tax or 15% for financial institutions, insurance and capitalisation companies ) 0% [50] 47.5% (27.5% income tax rate applied to annual income exceeding BR$55,976.15 [51] + 20% top social security tax rate for self-employed workers [52] )
John Jacob Astor saw his wife off to safety in No. 4 boat at 01:55 but was refused entry by Lightoller, even though 20 of the 60 seats aboard were unoccupied. [138] The last boat to be launched was collapsible D, which left at 02:05 with 25 people aboard; [140] two more men jumped on the boat as it was being lowered. [141]
The University of California, Los Angeles ( UCLA) [1] is a public land-grant research university in Los Angeles, California, United States. Its academic roots were established in 1881 as a normal school then known as the southern branch of the California State Normal School which later evolved into San José State University.
Africa is the world's second largest and second-most populous continent after Asia. At about 30.3 million km 2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth 's land area and 6% of its total surface area. [7] With 1.4 billion people [1] [2] as of 2021, it accounts for about 18% of the world's human population.
In 2017, out of the U.S. foreign-born population, some 45% (20.7 million) were naturalized citizens, 27% (12.3 million) were lawful permanent residents (including many eligible to become citizens), 6% (2.2 million) were temporary lawful residents, and 23% (10.5 million) were unauthorized immigrants.
Hydrogen peroxide ( H2O2) is a nonplanar molecule with (twisted) C 2 symmetry; this was first shown by Paul-Antoine Giguère in 1950 using infrared spectroscopy. [9] [10] Although the O−O bond is a single bond, the molecule has a relatively high rotational barrier of 386 cm −1 (4.62 kJ / mol) for rotation between enantiomers via the trans ...