Chapter 4 Physical Science Short Test
You need to answer each? To the best of ur ability.
Questions and Answers
- 1.
One of the first people to state that matter is made up of atoms was
- A.
Democritus
- B.
Aristotle
- C.
Dalton
- D.
Rutherford
Correct Answer
A. DemocritusExplanation
Democritus was one of the first people to propose the concept that matter is composed of indivisible particles called atoms. He believed that atoms were eternal, unchangeable, and infinite in number. Democritus' atomic theory was based on the idea that atoms differ in size, shape, and arrangement, which determines the properties of different substances. Although his atomic theory was not widely accepted during his time, it laid the foundation for the development of modern atomic theory.Rate this question:
-
- 2.
Dalton's model of an atom is best described as
- A.
A solar system
- B.
A solid sphere
- C.
A plum pudding
- D.
An electron cloud
Correct Answer
B. A solid sphereExplanation
Dalton's model of an atom is best described as a solid sphere because it proposed that atoms were indivisible and indestructible particles with no internal structure. This model suggested that atoms were uniform, dense, and had no empty spaces within them. However, this model was later replaced by more accurate models that described the internal structure of atoms, such as the electron cloud model.Rate this question:
-
- 3.
Who provided the first evidence that atoms contain subatomic particles?
- A.
Dalton
- B.
Rutherford
- C.
Thomson
- D.
Bohr
Correct Answer
C. ThomsonExplanation
Thomson provided the first evidence that atoms contain subatomic particles. He conducted the cathode ray tube experiment and discovered that the rays were composed of negatively charged particles, which he called electrons. This experiment proved the existence of subatomic particles within atoms and laid the foundation for the development of the atomic model. Dalton proposed the atomic theory, Rutherford conducted the gold foil experiment and proposed the nuclear model of the atom, and Bohr proposed the planetary model of the atom. However, Thomson's experiment was the first to provide evidence of subatomic particles within atoms.Rate this question:
-
- 4.
Almost all mass of an atom is located in its
- A.
Protons
- B.
Electrons
- C.
Electron cloud
- D.
Nucleus
Correct Answer
D. NucleusExplanation
The nucleus of an atom contains almost all of its mass. Protons and neutrons, which are both located in the nucleus, have significantly more mass than electrons. While electrons are negatively charged particles that orbit around the nucleus in an electron cloud, they have a negligible mass compared to protons and neutrons. Therefore, the correct answer is nucleus.Rate this question:
-
- 5.
Which particle is the least massive?
- A.
Proton
- B.
Electron
- C.
Neutron
- D.
Nucleus
Correct Answer
B. ElectronExplanation
The electron is the least massive particle among the options given. It has a much smaller mass compared to the proton and neutron, which are both found in the nucleus of an atom. The electron is a subatomic particle that orbits the nucleus and carries a negative charge. Its mass is approximately 1/1836th of the mass of a proton or neutron.Rate this question:
-
- 6.
All atoms of an element have the same
- A.
Mass #
- B.
# of isotopes
- C.
Atomic #
- D.
# of neutrons
Correct Answer
C. Atomic #Explanation
The atomic number of an element refers to the number of protons in the nucleus of an atom. Since all atoms of an element have the same number of protons, the correct answer is atomic #. The mass number refers to the total number of protons and neutrons in the nucleus, which can vary among different isotopes of the same element. The number of isotopes and the number of neutrons can also vary among different atoms of the same element.Rate this question:
-
- 7.
Why must indirect evidence be used to study the structure of atoms?
- 8.
In Thomson's experiment, why was the glowing beam repelled by a negatively charged plate?
- 9.
What is the difference between the atomic # and mass #?
- 10.
What does it mean to say that an atom is in an excited state?
Back to top