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How do you explain the enthalpy of vaporization?

Tables denote various enthalpies of vaporization that scientists use to calculate how much heat is needed to change a liquid to a gas. Oxygen has an enthalpy of vaporization of 6.82, methane's is 8.18, chlorine's is 20.41, and carbon tetrachloride's is 30.00 kJ/mol. Heavier substances require greater heat, such as aluminum at 284 kJ/mol and lead at 178 kJ/mol. When the boiling points of substances are higher, the enthalpies of vaporization are also higher.\nEnthalpy denotes energy added or taken away from atoms and molecules. When matter changes states, heat is added or taken aw..

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What type of object do you study with a stereo microscope?

Unlike other types of microscopes, a stereo microscope works on the basis of reflection of light from the surface of the sample under view and not on the basis of the light transmitted through an object. It has two objective lenses and two eyepieces, offering two angles of view. That is, both right and left eyes are used to view the samples under study. Although the use of two eyes makes the view greater, the image viewed under the stereo microscope is similar to that viewed under other microscopes, such as the compound microscope. Because it uses reflected light instead of light transmitted t..

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How do HeLa cells work?

The first cells of the HeLa line were harvested from Henrietta Lacks, a cancer patient, in 1951. Billions of HeLa cells, weighing approximately 20 tons, have since been cultured and distributed to medical research laboratories around the world. Research involving HeLa cells has generated over 11,000 patents, and the line was instrumental in developing treatments for cancer, AIDS and polio, as well as being used to test the safety of pharmaceuticals and consumer products.\nHeLa cells' immortality is the result of an unusual division sequence. In normal cells, chromosomes are bound at their..

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What are the names of the moons that orbit Mars?

Named for fear and panic, the two mythical horses that pulled the chariot of Mars, the Roman god of war, these two moons orbit relatively close to Mars: Phobos' orbit is 3,000 miles above the surface of the planet, and Deimos is not much farther out. Neither Phobos nor Deimos look like typical moons. They are not spherical like the larger satellites or moons of other planets in the solar system. Being smaller in size and irregular in shape, Phobos and Deimos are considered minor satellites; major satellites such as Earth's moon have more spherical shapes.

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How is the fern life cycle similar to the moss life cycle?

Mosses and ferns are the first and second oldest types of land plants, respectively. Mosses lack any sort of vascular system, and so rely purely on diffusion to distribute water through them. This greatly restricts their size. The easily visible parts of mosses are the gametophytes, which create gametes. When a sperm joins with an egg in the gametophyte, a sporophyte is formed, attached to and dependent on the gametophyte. The sporophyte, in turn, distributes spores which grow into gametophytes.\nIn ferns, this relationship is somewhat reversed. Fern sporophytes are much larger than the tiny g..

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What are some tools for converting CMYK colors to PMS colors?

CMYK is a color print process based on an additive method consisting of the four base colors: cyan, magenta, yellow and black. Pantone Matching System, also known as PMS, is a solid color matching system that blends colors to match those specified in the Pantone color guide. Due to the different processes behind the two systems, perfect color matches cannot be achieved when converting between CMYK and PMS; however, free approximation tools exist online.

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Who are some famous Filipino physicists?

Gregorio Zara discovered the law of electrical kinetic resistance, which is named the Zara Effect in his honor. He invented the two-way videophone in 1955, then turned his attention toward solar energy, inventing solar batteries, stoves and water heaters.\nCaesar Saloma made significant advances in the field of optics and invented optical microscope techniques. He became chancellor of the main campus of the University of the Philippines in 2011 and is editor-in-chief of the Philippine Journal of Science.\nDiosdado Banatao developed chips that accelerate computer speed. He was also involved wit..

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Who is Jane Goodall?

The techniques developed by Goodall and her discoveries in the African rainforest during the 1960s and 1970s have informed the work of the researchers who followed. Her findings altered previous conceptions of primate behavior and provided evidence for surprising similarities between chimpanzee and human group interactions. Goodall's discoveries challenged the preexisting beliefs that chimpanzees did not eat meat and that only man was capable of being a toolmaker.Goodall is also known for her philanthropic work in the areas of conservation, humanitarianism and animal welfare. She is the r..

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What is the function of the dorsal aorta?

In the first weeks of human development, the embryonic dorsal aortas, which travel the length of the embryo, are bilaterally paired, according to LifeMap Discovery. The paired aortas fuse into a single dorsal aorta, which becomes the thoracic and abdominal aorta.\nThe cranial portions, which are those areas toward the head, of the dorsal aorta, so named because of its position at the back side of the heart, contribute to the formation of internal carotid arteries, according to the University of Illinois at Chicago's Embryological Development of the Human.\nThe descending aorta's func..

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What is a medium-sized tephra called?

Tephra can cause many problems in addition to the accompanying volcanic eruption. Tephra clouds can spread hundreds of kilometers and cause periods of darkness affecting plant and animal life. These clouds reduce visibility and cause respiratory issues. They interfere with electric transformers and power lines and cause problems with communication devices. They may also start forest fires and are known to generate electricity for lightning. Larger tephra can collapse structures.

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