<span>I did some investigation and summarized the process and made a clearer explanation so those who are confused can imagine the process better :) A scientific theory attempts to explain and describe why things happen. Hypotheses are formed and experiments are done to validate or toss the hypothesis based on the data collected. The Atomic Theory has gone through lots of refining as a scientific theory. For instance, William Crookes conduced an experiment with cathode ray tubes powered by electricity that glowed when powered. Crookes placed an object in between the positive and negative electrode and concluded that the shadow made on the positive side was small particles of matter traveling from the negative side. But more evidence was needed so, later on, J.J. Thomson continued Crookes experiment. He tested what would happen if a negative or positive charged rod was placed along the ray tubes and if it would differ if a different element was used as the negative electrode. Thomson found out that the beam had negatively charged particles and that even if the negative electrode is substituted, the glow is still present, meaning that all elements also had the small negative particles. These particles(now known as electrons) were smaller than the atom and were added to the model of the atom dispersed throughout the neutrally charged atom inside its positive sphere. Now came along Rutherford hoping to support Thomsons model by firing positively charged particles at a thin gold foil thinking it would go straight through the foil, but instead it evenly distributed as they went through the foil, concluding that atoms have a small, dense nucleus(containing positive protons and most of the mass of the atom) that deflected the particles passing through. This was a drastic change in the model now knowing that 1 proton has 2000 times the mass of an electron, but its positive charge cancels the negative electron. After WW1, Chadwick and others were seeing that sometimes the mass of the atom was greater than the mass of the protons and the number of protons was less than the mass of the atom. So it was thought that there were extra electrons and protons adding mass in the nucleus but cancelling their charges, but Rutherford proposed a particle with mass but no charge and called it a neutron; made of paired protons and electrons. But scientists kept studying atoms since there was no evidence of the neutron. Chadwick repeated these experiments though, in hopes to find the neutron and succeeded in 1932, finding it in the nucleus with a close mass to the proton. Thanks to these experiments for refining a scientific theory, we now have a clearer model of the atom.</span>
<u>Answer:</u> The correct IUPAC name of the alkane is 4-ethyl-3-methylheptane
<u>Explanation:</u>
The IUPAC nomenclature of alkanes are given as follows:
- Select the longest possible carbon chain.
- For the number of carbon atom, we add prefix as 'meth' for 1, 'eth' for 2, 'prop' for 3, 'but' for 4, 'pent' for 5, 'hex' for 6, 'sept' for 7, 'oct' for 8, 'nona' for 9 and 'deca' for 10.
- A suffix '-ane' is added at the end of the name.
- If two of more similar alkyl groups are present, then the words 'di', 'tri' 'tetra' and so on are used to specify the number of times these alkyl groups appear in the chain.
We are given:
An alkane having chemical name as 3-methyl-4-n-propylhexane. This will not be the correct name of the alkane because the longest possible carbon chain has 7 Carbon atoms, not 6 carbon atoms
The image of the given alkane is shown in the image below.
Hence, the correct IUPAC name of the alkane is 4-ethyl-3-methylheptane
Answer: Group 1 would have the lowest electronegativity values.
Explanation:
Electronegativity is the power of an atom in a molecule to attract electrons. It is also synonymous with the oxidizing ability or non-metallic character of elements.
Generally, across a given period from left to right, electronegativity increases due to increasing nuclear charge and decreasing atomic radius ( or atomic size ). This is because there is a greater tendency for a smaller atom with higher nuclear attraction to attract electrons than a larger atom with a lower nuclear attraction due to the shielding effect of the nuclear attraction by the inner shell electrons on the outermost electrons in the larger atom.
Also, down a particular group, electronegativity generally decreases due to increasing atomic radius/size.
This is why metals are generally electropositive ( lose electrons ) and non-metals are electronegative ( gain electrons ) as they are both found more on the left and right sides of the periodic table respectively.
Answer:
- Option d. i<u><em>t is higher than the energy of both reactants and products</em></u>
Explanation:
<em>Activated complex</em>, also known as transition state, is the intermediate structure formed in the course of a chemical reaction.
The activated complex is very unstable and of short life: it is at the peak of the potential chemical diagram, and can transform either into the reactants (backward) or the products (forward).
The activation energy of the reaction is the energy needed to reach the activated complex, then both reactants and products are lower in potential chemical energy than the activated complex, which is what explains why the activated complex can transform into one or another, reactants or products.
