The elements listed in the choices are radioactive materials. These materials are very unstable because of the high neutron-to-proton ratio in the nucleus. Because of this, they spontaneously undergo nuclear reactions by giving off sub-particles in order to lower the ratio. They emit radiation in the form of alpha, beta or gamma.
Half-life is the length of time it needs to completely react half of the original amount. For example, it would take Bismuth 60.5 seconds to use up half of its amount. Therefore, the lower the half-life the faster the reaction is and the lesser the residual amount will be. With that being said, the answer would be Bismuth because it only takes seconds.
On April 26, 1986, the world's worst nuclear accident happened<span> at the </span>Chernobyl plant near Pripyat, Ukraine, in the Soviet Union. An explosion and fire in the No. 4 reactor sent radioactivity into the atmosphere. Plant operators made several mistakes, creating a poisonous and unstable environment in the reactor core. <span>A peculiarity of the design of the control rods </span>caused<span> a dramatic power surge as they were inserted into the reactor.</span>
Answer:
physical - soil fertility, soil drainage, slope angle, aspect, scenery, mineral potential etc.
economic - distance from markets, demand for different uses.
social - population size, legislation, government policies.
Explanation:
The sign of x cordinates change...if the object had a positive x cordinates the image will have negative x cordinates
Answer:
It made significantly better predictions of planetary positions in our sky
Explanation:
Of the following statements the one which was not a major advantage of Copernicus's Sun-centered model over the Ptolemaic model is that it made significantly better predictions of planetary positions in our sky. Both the model made similar predictions of planetary position in our sky. In fact the Ptolemaic model was even better than the Copernicus's heliocentric model when it came to positioning of planets.
