Science

Refine Search

What are the components of black powder?

Black powder has been around for thousands of years, as it was first discovered by alchemists in China sometime during the ninth century A.D. The charcoal that was used as the fuel source was normally from the willow tree, but charcoals from a wide variety of other woods work as well.\nMaking gunpowder involves finely grinding each of the ingredients and then mixing them together. The resulting powder is extremely reactive and explodes at the slightest touch of fire. In this reaction, the sulfur acts as a stabilizing agent, while the saltpeter provides extra oxygen to allow the carbon in the c..

Continue Reading

What is the difference between parasites and predators?

Although parasites do not kill their host, they harm the host by spreading pathogens, which often affect the host’s metabolism, reproductive activity and behavior. Alison N. P. Stevens, a professor in the Department of Biology at Mount Ida College, states in an article published on Nature Education that scientists classify parasites in two categories. Ectoparasites live and feed outside the body of their host, while endoparasites live inside the host’s body. Plants and animals, both vertebrate and invertebrate, serve as hosts. Examples of ectoparasites are bacteria, fungi, protozoa, ticks ..

Continue Reading

Why don't noble gases form compounds?

Atoms form compounds by losing, sharing or gaining electrons. The ultimate goal is to have a full valence shell. Noble gases are unmotivated to lose, gain or share electrons because they already have all the electrons required to be stable.\nOne exception that does form compounds is the noble gas xenon. Xenon can react with fluorine and oxygen in a process known as oxidation to form new molecular compounds. Radon, another noble gas, can also react with fluorine.

Continue Reading

What is the driving force behind the water cycle?

Earth's water is in constant motion as water at the surface exchanges places with the gaseous moisture and water droplets found in the atmosphere. As the sun warms the Earth, liquid water found in lakes and oceans on the planet's surface evaporates. Moisture within the atmosphere eventually cools and condenses, until liquid water or snow falls back to the Earth as precipitation. Runoff from rain eventually finds its way back to lakes and oceans, completing the most direct version of the water cycle.\nThe water cycle is able to move 495,000 cubic kilometers of moisture through the atm..

Continue Reading

What is the volume of 4.50 moles of nitrogen gas at STP?

Another method to find the answer is by using the Ideal Gas Law given as P x V = n x R x T, where at STP, the temperature is 32 degrees Fahrenheit or 273 degrees Kelvin, the constant R is 0.082057 L atm/mol K degrees, n is the number of moles and P is the pressure of 1 atm. By expressing the Ideal Gas Law as V = (n x R x T) and substituting for the variables n = 4.5, T =273 K, R= 0.082057, P= 1 atm, it is possible to find the volume as 100.8 L.

Continue Reading

What is it called when two forces are equal?

A force is a physical quantity that is either a push or a pull applied on an object. It can directly influence the motion of an object, change its direction or alter its shape. Forces can be broadly categorized into two types: balanced and unbalanced. Balanced forces have a resultant force equal to zero.When balanced forces are exerted on a stationary object, it remains at rest. A moving body also retains constant velocity and uniform direction when balanced forces act on it. However, these forces may alter the shape of a body by either stretching or compressing the object.An example that demo..

Continue Reading

How many chromosomes are in each daughter cell at the end of mitosis?

Mitosis involves the splitting of a cell and its content. According to the State University of New York, mitosis has five phases: interphase, prophase, metaphase, anaphase and telophase. During interphase, the cell prepares for mitosis, and chromosomes are usually not visible. In prophase, the chromosomes start to coil, the nuclear membrane wanes and a spindle-like formation appears. In metaphase, the chromosomes align for replication. In anaphase, the chromatid separates, doubling the number of chromosomes to 92. In telophase, the chromosomes uncoil, the nuclear membrane reappears and the cel..

Continue Reading

What is the molecular geometry of IF5?

The angle between each of the bonds in the molecule is 90 degrees for the four fluorine atoms making up the base of the pyramid, and 180 degrees for the single fluorine atom making up the pyramid's point. The two-dimensional structure of iodine pentafluoride is written out as a central iodine atom surrounded by five fluoride atoms in a star shape resembling an asterisk, but this is for convenience and does not correspond to the true shape of the molecule or the bond angles involved.\nBromine pentafluoride has a very similar shape to iodine pentafluoride.

Continue Reading

How do you convert PDT to GMT?

Know the difference between the time zonesGMT is normally 8 hours ahead of the Pacific Standard time zone on the West Coast of the United States. However, during the period when Daylight Saving Time is observed in the United States, Pacific Standard Time changes to Pacific Daylight Time by going forward one hour. The difference between GMT and PDT is 7 hours.Add 7 hours to PDTTo convert a time from PDT to GMT, add 7 hours to the time in PDT. For example: 4 a.m. + 7 hours = 11 a.m.Label the answerTo be precise, label the time with the correct time zone. Ensure the date is correct also, because ..

Continue Reading

What is the thermal conductivity of brass?

Diamond, being a pure material, has an extremely high thermal conductivity at approximately 1,000 watts per meter kelvin. In contrast, most liquids and gases, as well as many solids, are not as thermally conductive as brass. For example, atmospheric air, which is comprised of gaseous nitrogen, oxygen, carbon dioxide and other trace elements, has a thermal conductivity of 0.024 watt per meter kelvin.

Continue Reading
Showing 381 to 390 of 10000 (1000 Pages)