Explain how the atomic theory was modified from dalton's theory to rutherford's. include and explanation of why the theory was modified

The structure of matter has been studied since the fifth century BC, when the first idea about its constitution arose. The philosophers Leucippus and Democritus argued that matter could not be infinitely divided into an indivisible unity called an atom. These speculations were replaced by models based on experimental studies after thousands of years.

Based on the weighted laws of Lavoisier and Proust, scientist John Dalton, around the year 1808, elaborated his theory on matter, known as Dalton's atomic theory. The main conclusions of Dalton's atomic model were: matter is made up of extremely small particles called atoms; atoms are massive and indivisible spheres; atoms with the same properties constitute a chemical element; Different elements are constituted by atoms with different properties and chemical reactions are rearrangements, joining and separation of atoms.

After Dalton, based on experiments with electric charges, the English scientist Joseph John Thomson in the late nineteenth century concluded that the atom was not an indivisible sphere, as Dalton suggested. The experience that led to the elaboration of this model consisted in the emission of cathode rays, where negative particles were attracted by the positive pole of an external electric field. These negative particles were called electrons, and to explain the neutrality of matter, Thomson proposed that the atom be a sphere of positive electric charge, where the electrons would be evenly distributed, setting an electrical equilibrium.

Years later, in the early twentieth century, scientist Ernest Rutherford, using radioactivity, discovered that the atom was not a massive sphere, as Dalton's atomic theory suggested. Thus emerged a new atomic model.

Rutherford bombarded a 0.00001 cm gold sheet surrounded by a zinc sulfide screen, with α particles from the polonium element protected by a perforated lead block. This experience revealed that the vast majority of particles passed through the gold blade, while other particles passed and suffered slight deviations, and a very small amount did not cross the blade. The pathway followed by the α particles was detected due to the luminosity reflected on the zinc sulfide screen.

Comparing the number of particles emitted with those of deviated particles, Rutherford deduced that the mass of the gold blade would be located in small points, called nuclei, and that the radius of the atom should be 10,000 to 100,000 times greater than the radius of the nucleus. atom formed by empty spaces. Most particles have crossed the blade through these spaces. The explanation for the deviated α particles was given that the positive core of the gold slide repels the also positive alpha particles. The particles that did not cross would have collided head-on with these nuclei, being bounced.

Rutherford's atomic model concluded that the atom was composed of a small positively charged nucleus neutralized by a negative region, called the electrosphere, where electrons rotated around the nucleus.

1.solid

2.carbon dioxide

3.helium

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.