1.
Greek Scientist who suggested that the world was made up of 2 things: Empty space and atoms.
Correct Answer
C. Democritus
Explanation
Democritus is the correct answer because he was a Greek scientist who proposed the idea that the world is composed of two fundamental elements: empty space and atoms. He believed that atoms are indivisible and indestructible particles that make up all matter. This concept of atoms laid the foundation for modern atomic theory and greatly influenced the development of science. Aristotle, Newton, and Millikan were also important scientists, but they did not specifically propose the idea of atoms and empty space.
2.
Proposed matter was continuous and wasn't made of hyles (smaller than atoms).
Correct Answer
D. Aristotle
Explanation
Aristotle believed that matter was continuous and not made up of smaller particles (hyles). He proposed that matter could be infinitely divided, with no smallest unit. This view contrasted with the atomic theory proposed by Dalton, which suggested that matter was composed of indivisible atoms. Rutherford and Bohr, on the other hand, made significant contributions to atomic theory by discovering the atomic nucleus and proposing the concept of electron orbits, respectively.
3.
Believed nature was made up of elements, and elements were made of atoms.
Correct Answer
A. Newton
Explanation
Newton is the correct answer because he believed that nature was composed of elements, and these elements were made up of atoms. Newton's ideas about the composition of matter laid the foundation for the development of modern atomic theory. His work in physics and mathematics, particularly his laws of motion and universal gravitation, revolutionized our understanding of the natural world.
4.
Observed experimental observations made by other concurring chemical reactions.
Correct Answer
B. Dalton
Explanation
The given answer, Dalton, is likely the correct answer because Dalton's atomic theory was based on observed experimental observations made by other concurring chemical reactions. Dalton's theory proposed that atoms were indivisible and that chemical reactions occurred when atoms combined or separated. This theory was supported by various experimental evidence, such as the law of multiple proportions and the law of conservation of mass. Therefore, Dalton's atomic theory is a reasonable explanation for the observed experimental observations mentioned in the question.
5.
Made the first, accurate measurement of an electron’s charge.
Correct Answer
A. Millikan
Explanation
Millikan is the correct answer because he conducted the famous oil drop experiment in 1909, which allowed him to determine the charge of an electron accurately. By balancing the gravitational and electrical forces acting on oil droplets, he was able to calculate the charge of individual electrons. This experiment provided the first direct measurement of the charge of an electron and helped to establish the fundamental understanding of atomic structure and electricity. Thompson, Democritus, and Planck are not associated with making the first accurate measurement of an electron's charge.
6.
Found high energy particles with no charge called neutrons.
Correct Answer
D. Rutherford
Explanation
Rutherford is the correct answer because he is known for his discovery of the atomic nucleus and the existence of neutrons. In his famous gold foil experiment, Rutherford observed that some of the alpha particles he shot at the gold foil were deflected, which led him to propose the existence of a dense, positively charged nucleus at the center of the atom. This discovery revolutionized our understanding of atomic structure and confirmed the presence of neutral particles called neutrons.
7.
Made a model of an atom (planetary) which used Quantum Theory.
Correct Answer
A. Bohr
Explanation
Bohr is the correct answer because he developed the Bohr model of the atom, which is a planetary model that incorporates quantum theory. This model proposed that electrons orbit the nucleus in specific energy levels, and that they can transition between these levels by absorbing or emitting energy in discrete packets called quanta. This model was a significant advancement in understanding atomic structure and laid the foundation for further developments in quantum mechanics.
8.
Figured out under a closed system, mass after the change equal to the mass before the change.
Correct Answer
B. Lavoisier
Explanation
Lavoisier is the correct answer because he is known for his work in the field of chemistry, particularly in the study of mass conservation. Lavoisier's experiments and observations led him to propose the Law of Conservation of Mass, which states that mass is neither created nor destroyed in a chemical reaction. This means that in a closed system, the total mass before and after a change or reaction will remain the same. Lavoisier's contribution to the understanding of mass conservation makes him the most appropriate choice for the given statement.
9.
Discovered that cathode rays consist of electrons. Also calculated the mass of the proton was about 1836x the mass of an electron.
Correct Answer
D. Thompson
Explanation
Thompson is the correct answer because he discovered that cathode rays consist of electrons and also calculated that the mass of the proton was about 1836 times the mass of an electron. This discovery and calculation were significant contributions to the understanding of atomic structure and the existence of subatomic particles.
10.
Assumed energy is given off in little packets or quantas. Further stated that the amount of energy given off is directly related to the frequency of the light emitted.
Correct Answer
A. Planck
Explanation
Max Planck proposed the concept of quantized energy, which states that energy is emitted or absorbed in discrete packets called quanta. This idea revolutionized the field of physics and laid the foundation for quantum mechanics. Planck also introduced the Planck constant, which relates the energy of a quantum to its frequency. This means that the amount of energy given off by a system is directly proportional to the frequency of the light emitted. Therefore, Planck is the correct answer as he is the scientist associated with the concept of quantized energy and its relationship to frequency.
11.
Explained the origin of the energy release during nuclear change.
Correct Answer
C. Einstein
Explanation
Einstein is the correct answer because he developed the theory of relativity, which explains the relationship between mass and energy. According to his famous equation, E=mc^2, energy can be released during a nuclear change when a small amount of mass is converted into a large amount of energy. This concept revolutionized our understanding of nuclear reactions and has been confirmed by numerous experiments and observations.
12.
Observed that specific substance always contain elements in the same ratio by mass.
Correct Answer
B. Proust
Explanation
Proust's law of definite proportions states that a given compound always contains the same elements in a fixed ratio by mass. This means that regardless of the amount or size of the sample, the elements within the compound will always be present in the same proportion. Proust's law was a significant contribution to the understanding of chemical reactions and the development of the atomic theory.