Answer:
Among the different types of scientific knowledge hypotheses are likely to be modified or discarded most frequently. Long ago in the 1600's scientists discarded the phlogiston theory because the new evidence didnt support it.
Explanation:
Hypothesis is the assumption of something possible or impossible to draw a consequence and is provisionally established as the basis for an investigation and which can confirm or deny its validity. For this reason, within scientific research, hypotheses are so important and so changeable that they are modified or discarded more frequently within scientific knowledge.
Based on a work by Johann Joachim Becher, the German scientist Georg Ernst Stahl created the phlogiston theory that said combustion occurred with certain materials because they had an “element” or a common flammable principle that was released at the time of burning . This theory was abandoned because there was no evidence, even through scientific experiments, to prove that this theory is true.
Answer:
₈₆²²²Rn → ₈₄Po²¹⁸ + H₂⁴
Explanation:
The given nuclear reaction shows alpha decay.
₈₆²²²Rn → ₈₄Po²¹⁸ + H₂⁴
Properties of alpha radiations:
Alpha radiations are emitted as a result of radioactive decay. The atom emit the alpha particles consist of two proton and two neutrons. Which is also called helium nuclei. When atom undergoes the alpha emission the original atom convert into the atom having mass number less than 4 and atomic number less than 2 as compared to parent atom the starting atom.
Alpha radiations can travel in a short distance.
These radiations can not penetrate into the skin or clothes.
These radiations can be harmful for the human if these are inhaled.
These radiations can be stopped by a piece of paper.
₉₂U²³⁸ → ₉₀Th²³⁴ + ₂He⁴ + energy
Reflection, refracting, and the energy levels of molecular orbitals
Answer:
The atomic mass of the boron atom would be <em>10.135</em>
Explanation:
This is generally known as relative atomic mass.
Relative atomic mass or atomic weight is a physical quantity defined as the ratio of the average mass of atoms of a chemical element in a given sample to the atomic mass of 1/12 of the mass of a carbon-12 atom. Since both quantities in the ratio are masses, the resulting value is dimensionless; hence the value is said to be relative and does not have a unit.
<em>Note that the relative atomic mass of atoms is not always a whole number because of it being isotopic in nature.</em>
- <em>Divide each abundance by 100 then multiply by atomic mass</em>
- <em>Do that for each isotope, then add the two result. Thus</em>
Relative atomic mass of Boron = (18.5/100 x 11) + (81/100 x 10)
= 2.035 + 8.1
= 10.135
