QUESTION 1
The root word “di” means “two,” so the word “diatomic” refers to _____.
OPTIONS
a molecule with two atoms
QUESTION 2
In paragraph 2, attraction and repulsion refer to _____.
OPTIONS
atomic theories
QUESTION 3
How did Ernest Rutherford’s experiment relate to J.J. Thomson’s work?
OPTIONS
Rutherford repeated Thomson’s experiment and confirmed the results.
QUESTION 4
Which scientist discovered the neutron and gave us the current basic model of the atom?
OPTIONS
James Chadwick
QUESTION 5
What contribution did J.J. Thomson make to the development of atomic theory?
OPTIONS
found that atoms are made of smaller particles
. Since the ancient Greek civilization, people have wondered about the nature of the atom. The atom is the basic building block of matter. The word atom comes from the Greek language. A is a prefix meaning not. The word tomos means cut. Therefore, atomos or atoms means cannot be cut or divided.
. Many people helped develop the theory of atoms. The first was a Greek named Democritus in the 4th century BC. He proposed that all matter was made of tiny particles. Democritus thought that empty space filled the area between the solid atoms. That concept of the atom was unchanged for centuries. Then an English scientist, John Dalton, proposed an atomic theory in 1803. Atomic theory says that atoms are solid with an atomic mass. They can react because of the forces of attraction and repulsion. In 1873, James Clerk Maxwell proposed that electric and magnetic fields filled the empty space in atoms.
. In 1897, J. J. Thomson discovered the first subatomic particles, which he called electrons. His experiments found that these electrons have a negative electric charge. He then calculated that they had a much smaller mass than even the smallest atom. Thomson proposed the plum pudding model of the atom. This model says that negatively-charged electrons are mixed inside a cloud of positive charge. He thought they were like chunks of plum inside pudding.
. Ernest Rutherford did an experiment in 1909 to test Thomson's model. His results did not agree with the plum pudding model. Instead, Rutherford was the first to show the nuclear model of the atom. This model shows that the center of an atom contains positively-charged protons (p+) surrounded by the negatively-charged electrons (e-). In 1932, Sir James Chadwick found the neutrally charged neutron (n0). The atomic model now seemed complete after all these discoveries.
. Many people had a hand in developing atomic theory as we know it today. However, scientists continue to study the atom. They have found many more details about atoms. As we learn about this building block of matter, the nuclear model of the atom will continue to change.
Now answer each one
QUESTION 1
The root word “di” means “two,” so the word “diatomic” refers to _____.
OPTIONS
forces within the atom
a molecule with two atoms
negatively-charged electrons
positively-charged protons
QUESTION 2
In paragraph 2, attraction and repulsion refer to _____.
OPTIONS
electric and magnetic fields
atomic theories
tiny particles
solid atoms
QUESTION 3
How did Ernest Rutherford’s experiment relate to J.J. Thomson’s work?
OPTIONS
Rutherford looked for magnetic fields, while Thomson looked for electric fields.
Rutherford repeated Thomson’s experiment and confirmed the results.
Rutherford tested a conclusion based on Thomson’s results.
Rutherford had not known about Thomson’s experiment.
QUESTION 4
Which scientist discovered the neutron and gave us the current basic model of the atom?
OPTIONS
James Maxwell
John Dalton
James Chadwick
Sir Isaac Newton
QUESTION 5
What contribution did J.J. Thomson make to the development of atomic theory?
OPTIONS
said that atoms are solid masses
showed that electrons surround a dense nucleus
found that atoms are made of smaller particles
proposed that atoms contain electric fields
1 answer
3 answers