Science

Refine Search

What did Niels Bohr discover about atoms?

Ernest Rutherford discovered that atoms had a dense nucleus surrounded by a cloud of electrons. However, when the principles of classical physics are applied to this model, the electrons immediately spiral down to the nucleus and cause the atom to collapse. Because this does not happen in the real world, Bohr hoped to find a model that worked.\nHe combined Rutherford's model with Planck's recent idea that energy came in packets of a fixed amount, known as quanta. Rather than being able to orbit at any distance from the nucleus, electrons can only occupy certain fixed energy levels. W..

Continue Reading

What are examples of solutes and solvents?

"Like dissolves like" refers to the fact that polar solutes will dissolve in polar solvents and non-polar solutes will only dissolve in non-polar solvents. Polar solutes cannot dissolve in non-polar solvents. Water is a polar solvent, salt and sugar are both polar solutes. To dissolve iodine, which is non-polar, a solvent such as ethyl acetate would be needed and it would not dissolve into water.The polarity of each solvent or solute substance depends on the covalent bonds it has between atoms. When two non-metal atoms bond, two electrons are shared between each of them. In covalent bonds, the..

Continue Reading

What are synovial joints?

The BBC explains that all synovial joints consist of synovial fluid, a synovial memrane, cartilage, a tendon and a ligament. Cartilage serves as a shock absorber and reduces friction. Synovial fluid lubricates joints, while synovial membrane produces synovial fluid. Tendons join muscle-to-bone, enabling movements, whereas ligaments join bone-to-bone movements and stabilize the joint. Limbs use joint actions to move in various directions.\nThere are six ways that synovial joints move, says Dawn A. Tamarkin of the Springfield Technical Community College. Ball-and-socket joints allow for freedom ..

Continue Reading

What is the difference between the terms biosphere and community?

The process of change, or succession, that takes place in an ecological community can be of two types: primary and secondary. In a primary succession a community develops in a newly exposed landform where none existed before, while in a secondary succession, a replacement community colonizes an ecosystem that was recently damaged or destroyed by an upheaval, such as a forest fire or flood.In the global ecological closed system of the biosphere, the variety of ecological systems are divided into biomes by geographic regions. Some examples of biomes are the aquatic biomes, such as lakes, streams..

Continue Reading

How high are clouds?

The three main types of clouds are stratus clouds below 6,500 feet, "alto-" clouds such as altostratus and altocumulus between 6,500 and 20,000 feet and cirrus clouds 20,000 feet and above. Thunderstorm clouds can reach as high as 50,000 feet, or more than nine miles high.\nClouds form when invisible humidity in the air cools and condenses on dust or salt particles and turns into ice crystals or water droplets and becomes visible.

Continue Reading

Which planet has the lowest density?

Water has a density of 1 gram per cubic centimetre, so Saturn is less dense than water. This means that Saturn would float if there were a bathtub big enough to hold the planet. In contrast to Saturn, Earth is the densest planet with a density of 5.51 grams per cubic centimetre. Saturn is made up of mostly hydrogen and helium. It is the second largest planet after Jupiter and is big enough to contain over 760 Earths. The four inner planets of the Solar System are denser than the outer gas giants and are made up of rocks and heavy metals.

Continue Reading

What elements make up sugar?

Under a microscope, a molecule of sugar looks like a cube. When cooking, acid is added to the sugar to break the cube apart. The acid breaks the sucrose down into fructose and glucose.\nSugar exists in most plants. However, it is harvested primarily from sugarcane. Sugarcane is harvested all around the world with Brazil as the world's largest producer of sugar.

Continue Reading

What is the correct way to read a tape measure?

The longest and only numerically-indicated mark on the tape is the whole inch. It's the easiest mark to see and use. The second-longest is the half-inch mark. This mark falls into the "no numeral" zone, but it divides the inch into only two parts and using it is a simple calculation. Next comes the quarter-inch mark, the third longest mark that divides the inch into four sections.\nNext smaller is the eighth-inch mark, which divides the inch into eight sections. Measurements this fine should be written down, as they are difficult to memorize. The smallest mark on the tape measure is the s..

Continue Reading

How many volts are in a lightning bolt?

Positive lightning, which comprises less than 5 percent of all lightning, originates on top of the clouds, rather than the lower portion of the storm, as negative lightning. These type of lightning can travel up to 25 miles horizontally in the air before they strike the ground and are sometimes called "bolts from the blue." Because of the greater distance to the ground, they develop much higher voltages.

Continue Reading

What can disrupt genetic equilibrium?

Mate selectivity means that, in a given population, individuals with certain genetic traits are favored by mates over those without those traits. Whether or not such a trait helps an animal survive, if it is able to breed more, its particular genetic traits become more prevalent in the population. Natural selection affects populations in the same way, but instead of occurring because of mate preferences, it affects which organisms survive long enough to breed.\nWhen individuals of a species move from one population to another, this decreases the genetic variability within the population that t..

Continue Reading
Showing 7221 to 7230 of 10000 (1000 Pages)