Answer:
Phosphorus-28 undergoes beta-minus decay to produce
- an electron,
- a Silicon-28 nuclei, and
- an electron antineutrino.
Explanation:
In simple words, when a nucleus undergoes beta-minus decay, a neutron is converted to a proton. An electron and an electron antineutrino will be released.
.
One way to tell whether a neutron is converted to a proton, but not vice versa, is to check the sum charges on the two sides of this equation.
- Left-hand side: 0. Neutron is neutral.
- Right-hand side: 1 + (-1) = 0. Each proton carries a charge of +1. Each electron (beta-minus particle) carries a charge of -1. Antineutrinos are neutral.
The charges on the two sides of this equation is the same. Hence this nuclear equation is possible (but not necessarily correct; however, if the proton and the neutron are in the wrong place the charge won't even be the same.)
Since the mass number of a proton and a neutron are both 1, the overall mass number of the atom will stay the same.
The atomic number is the number of protons in each atom. That number determines the symbol and the chemical properties of the atom. When one neutron in an atom is converted to a proton, the atomic number of the atom will increase by 1.
The atomic number of the daughter nucleus, silicon, is 14. It takes a parent nucleus with atomic number 
to produce a silicon atom. Refer to a modern periodic table. Atomic number 
corresponds to the element aluminum.
Also, the mass number of the daughter nucleus is 28. Since the mass number would stay the same in a beta decay, the mass number of the parent nucleus would also be 28. In other words, it takes an aluminum-28 atom to undergo beta-decay to produce a silicon-28 atom.
Complete the other details (electron and electron antineutrino) to obtain the equation
.
<span>The Persian Wars mark an important turning point not only in Greek history but, indeed, in the course of all European civilization. First and foremost, because of its victory Greece was saved from the threat of external rule and could develop on its own. Handed this independence, the Greeks chose to follow a path which forever changed the course of modern life. Without their success in this conflict, they would, no doubt, never have had the liberty, means or conviction to invent, discover or create all they did: not just history but philosophy, science, drama, art, architecture, indeed most of the cornerstones of modern civilization.
Another consequence of this victory, less immediate but equally important, was that it prevented the Persians from dominating the lands to the west of Greece—as noted above, it's likely the fertile fields of Italy and Sicily, not the rough dust of Greece, were the real target of Xerxes' imperial designs—and there a tiny settlement called Rome had just begun to sprout, at that moment hardly a dot on the map, but it would later develop into a crucial player in the history of the West. Rome won freedom, too, in the Persian Wars, without ever fielding a single fighter. It's impossible to imagine how vastly different our world would be if Persia had conquered or exterminated the Romans before they'd ever had a chance to grow.
Thus, the Greeks laid the groundwork for later Western culture, and Herodotus the foundation for understanding it. If so many of his facts look suspect or even prove incorrect, if he sometimes seems to set speculation and scandal over sober criticism and science, before condemning him we should recall that he founded this entire enterprise called history, a discipline which still bears the name he gave it. His critics should also bear in mind it's only because Herodotus set us on this path that we can even scorn his methods in the first place. To this most uncommon "common man," we owe an enormous collective debt.</span>
Answer:
52. The alcohol USED => methanol, CH3OH
The carboxylic acid USED => propanoic acid, CH3CH2COOH.
53. The alcohol USED => Ethanol, CH2CH3OH
The carboxylic acid USED => Formic acid, HCOOH.
Explanation:
52. To obtain Methyl propanoate, CH3CH2COOCH3, we simply react propanoic, CH3CH2COOH and methanol, CH3OH together as shown below:
CH3CH2COOH + CH3OH —> CH3CH2COOCH3 + H2O
The alcohol used: methanol, CH3OH
The carboxylic acid used: propanoic acid, CH3CH2COOH.
53. To obtain Ethyl methanoate, HCOOCH2CH3, we simply react
Formic acid, HCOOH and ethanol, CH3CH2OH together as show below:
HCOOH + CH3CH2OH —> HCOOCH2CH3 + H2O
The alcohol USED => Ethanol, CH2CH3OH
The carboxylic acid USED => Formic acid, HCOOH.
The Environmental Protection Agency (EPA) refrigerant management regulations would exempt any refrigerant from venting problem when it determines that the refrigerant in an appliance do not pose a threat to the environment (surrounding) if released.
A refrigerant can be defined as any chemical substance that undergoes a phase change (liquid and gas) so as to enable the cooling and freezing of materials. They are typically used in air conditioners, refrigerators, water dispensers, etc.
In the United States of America, the Environmental Protection Agency (EPA) is a governmental agency which was established by U.S Congress and it is saddled with the responsibility of overseeing all aspects of pollution, environmental clean up, degradation, pesticide use, contamination, and hazardous waste spills. Also, EPA research solutions, policy development, and enforcement of regulations through the resource Conservation and Recovery Act.
Simply stated, the Environmental Protection Agency (EPA) is the governmental agency set up to ensure that various industries, factories and people comply with laws and regulations concerning the environment.
In conclusion, appliances such as a refrigerator, air conditioner (AC), etc., whose refrigerants do not pose a threat (potentially cause damage) to the environment if released are typically exempted by the EPA's refrigerant management regulations.
