Experiments suggest that organic molecules could have been synthesized in the atmosphere of early Earth and rained down into the oceans. RNA and DNA molecules — the genetic material for all life — are just long chains of simple nucleotides. Replicating molecules evolved and began to undergo natural selection.
A 70.-kg person exposed to ⁹⁰Sr absorbs 6.0X10⁵ β⁻ particles, each with an energy of 8.74X10⁻¹⁴ J.
<h3>What is β⁻ particles ?</h3>
A beta particle, also known as a beta ray or beta radiation (symbol ), is a highly energetic, swiftly moving electron or positron that is released during the radioactive disintegration of an atomic nucleus. Beta decay occurs in two ways: decay and + decay, which result in the production of electrons and positrons, respectively.
In air, beta particles with an energy of 0.5 MeV have a range of roughly one meter; the range is energy-dependent.
Ionizing radiation of the sort known as beta particles is regarded, for the purposes of radiation protection, as being more ionizing than gamma rays but less ionizing than alpha particles. The damage to live tissue increases as the ionizing effect increases, but so does the radiation's penetration power.
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Answer:
A molecular compound is usually composed of two or more nonmetal elements. Molecular compounds are named with the first element first and then the second element by using the stem of the element name plus the suffix -ide.
Answer:
No matter how well how much you accomplish, or how much good you put into the world, you will always have haters. An unfortunate aspect of life is that some people hate when others do well.It’s just a way of life.some people just are jealous but dont let people brake you down.
Explanation:
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<span>E=hν</span> where E is the energy of a single photon, and ν is the frequency of a single photon. We recall that a photon traveling at the speed of light c and a frequency ν will have a wavelength λ given by <span>λ=<span>cν</span></span>λ will have an energy given by <span>E=<span><span>hc</span>λ</span></span><span>λ=657</span> nm. This will be <span>E=<span><span>(6.626×<span>10<span>−34</span></span>)(2.998×<span>108</span>)</span><span>(657×<span>10<span>−9</span></span>)</span></span>=3.0235×<span>10<span>−19</span></span>J</span>
So we now know the energy of one photon of wavelength 657 nm. To find out how many photons are in a laser pulse of 0.363 Joules, we simply divide the pulse energy by the photon energy or <span>N=<span><span>E<span>pulse </span></span><span>E<span>photon</span></span></span>=<span>0.363<span>3.0235×<span>10<span>−19</span></span></span></span>=1.2×<span>1018</span></span>So there would be <span>1.2×<span>1018</span></span><span> photons of wavelength 657 nm in a pulse of laser light of energy 0.363 Joules.</span>
