Science

Refine Search

How much does silica sand cost?

Silica sand is composed of quartz and is also called "frac sand" since it is used in the production of natural gas and oil. Hydraulic fracturing, known as "fracking," involves pushing high volumes of water, chemicals and silica sand into a gas or oil well. The mixture holds open the fractured rocks, allowing gas or oil to flow out. The sand must be of a certain quality to be used in the process. The cost per ton is affected greatly by the cost of transporting the sand from one location to another.

Continue Reading

What impact do humans have on the carbon cycle?

Carbon dioxide forms part of the Earth's atmosphere, along with other gases such as methane and oxygen. These gases operate in a delicate balance, working harmoniously to regulate temperature, water storage and precipitation. The influx of excessive amounts of carbon dioxide in the air disturbs this balance. Carbon dioxide molecules function as temperature regulators. With less carbon dioxide in the atmosphere, temperatures on Earth fall.More carbon dioxide, however, brings warmer temperatures. This triggers accumulation of water vapor and additional precipitation. In oceans, rising carbo..

Continue Reading

What is absolute dating?

In the field of archeology, the term "absolute" is somewhat misleading. Chronometric or calendar dating is a better choice. Using these methods, the scientist determines a date range for when an event took place rather than where it fits in the overall record. They do not necessarily determine a specific date. The techniques scientist need for absolute dating did not become available until the later half of the 20th century.\nAbsolute dating uses clues, such as the emperor's face on a coin, to date an artifact. Tree ring dating offers over 1,000 years of clues in dates of artifacts from t..

Continue Reading

What colors are mixed together to make gray?

Learn to Draw and Paint presents several methods to get nuanced shades of gray paint. The primary colors of red, yellow and blue mixed together produce gray. Mixing the secondary colors of orange, violet and green together will also produce gray. Two complementary colors directly across from one another on the color wheel make gray as well. Black can be mixed with any color to neutralize it, with the result being gray with the original color's undertones.

Continue Reading

How wide can a tornado be at the ground?

Researchers don't know enough about tornadoes to accurately predict how wide a tornado could possibly be. The width of tornadoes can only be measured indirectly, either by measuring the width of the destructive track left by the tornado or by analyzing meteorological data that can be inconclusive. There is no official measurement for the length or speed of a tornado. The Enhanced Fujita scale, which ranks tornadoes from 0 to 5, only takes into account the damage caused by the storm.

Continue Reading

What is the most probable ion formed from oxygen?

Water is an abundant oxide which forms when two hydrogen atoms bond with an oxide ion. Another oxide ion compound that forms readily is ferric oxide, formed when 3 oxide ions bond with 2 iron (III) ions. This compound, in the presence of water, creates rust. Carbon can oxidize with one or two oxide ions forming carbon monoxide and carbon dioxide.

Continue Reading

What are strong vs. weak acids?

Hydrogen chloride is a strong acid because it rapidly forms hydrochloric acid when added to water. Since the reaction is less likely to reform the reactants, the reaction is marked with an arrow pointing to the products. Sulfuric acid and nitric acid are strong acids as well. Strong acids have lower pH values due to the high concentration of hydrogen ions in the solution.\nOn the other hand, a weak acid does not ionize 100 percent when dissolved in water. For example, ethanoic acid is a weak acid that produces hydroxonium and ethanoate ions when placed in water. The acid does not fully dissolv..

Continue Reading

Who discovered lanthanum?

Mosander was looking for impurities in cerium when he found lanthanum. Classified as a metal, lanthanum is part of the lanthanide group. This rare-earth metal has the atomic number 57 and the symbol La. It is used to make carbon arc lights, and a form of it is used in camera lenses. This silver-white element is soft and ductile. It is highly reactive for a rare-earth metal and oxidizes in the air quickly.

Continue Reading

What feature is common to prokaryotes, fungi and plants?

Prokaryotes are single-celled organisms with no nuclei nor organelles. Their genetic material consists of rings of DNA residing in the cell body. Eukaryotes range from unicellular bacteria to the multi-cellular higher animals. Their cells contain a nucleus holding DNA in the form of chromosomes. Eukaryotes also have organelles, or structures specialized for cellular activities. All eukaryotic cells contain mitochondria, responsible for extracting energy from carbohydrates. Plant cells contain chloroplasts, which use the energy of sunlight to produce carbohydrates. DNA fingerprinting offers pro..

Continue Reading

What are the symptoms of air pockets in the lungs?

These air pockets form after the lining between air sacs is destroyed due to years of smoking. Patients often feel breathless during routine activities because the muscles responsible for breathing tire out more quickly as they try to expel larger volumes of air. Shortness of breath is the most common symptom of emphysema, notes WebMD. Wheezing, coughing and chest tightness may also occur with this disease.\nStages of emphysema are measured by forceful expiratory volume, which is the amount of air a patient can exhale in one second. The mildest stage of emphysema has an FEV of 80 percent or gr..

Continue Reading
Showing 7381 to 7390 of 10000 (1000 Pages)