Upgrade to remove ads
Unit 1 Investigation 4
Terms in this set (65)
What force keeps the nucleus together?
Strong Nuclear Force
Why was Bohr's model incorrect?
He said that electrons fly around on a fixed orbit like a planet
What part of the atom takes up the most space (volume)
Why do electrons spend most of their time near the nucleus according to the probability model?
the electrical force of the protons (+) and electrons (-) is strongest near the nucleus
Which model is currently the accepted model today?
How do I determine the neutrons of an atom by looking at the periodic table?
Atomic mass rounded to nearest whole number minus the protons (the atomic number)
How do I determine the number of protons of an atom from the periodic table?
Look at the atomic number (top number)
How many electrons are in Gallium?
How many neutrons are in Gallium?
How many protons are in Gallium? Ga
What is the correct AMU of a Proton, Neutron and Electron?
Proton= 1 AMU Neutron =1 AMU Electron = 0 AMU
If an atom gains or loses neutrons..
The mass changes but the atom's identity remains the same
Used the study light to determine that electrons had a specific orbit and velocity from the nucleus.
Electrons are more often found close to the nucleus and less likely found farther away from the nucleus
Examine the two diagrams below closely. What can explain the difference in the two paths of the electrons?
there is a greater charge on the plates in diagram A
In the diagram above an electron is shot from a cathode tube. The path of the electron is deflected towards the plate labeled B. What is the charge on plate A?
There is only one change to the variables which JJ Thomson made when he experimented. What did this one change in his experiment tell him?
All electrons have the same mass and charge
JJ Thomson changed the type of metal he used in his cathode ray experiment using gold, silver and iron. What conclusion did he come to as a result of this change?
The electrons coming from each type of metal had the same mass
According to the plum pudding model, negative electrons were..
suspended within a positive substance of electric charge.
What evidence did JJ Thomson discover to explain that all electrons were negative?
The electrons in the cathode ray beam ALWAYS moved toward the positively charged plate
JJ Thomson became the first person to discover something smaller than the atom called the...
An atoms' small, dense, positively charged center is called....
Atoms have positive and negative areas in them which creates...
An overall neutral charge
Why was it so surprising that the nucleus contained protons packed so tightly together?
Protons all have the same charge and like charges repel
If the atom were the size of a sprinkle how thick would a strand of air be?
1 football field
Why doesn't the strong nuclear force keep the electrons from leaving the atom?
The strong nuclear force only acts at very tiny distances
Why is it easier to remove electrons from the atom than is it to remove protons from the atom?
The strong nuclear force is much stronger than the electric force
What did Rutherford propose as a reason for why the positive particles called protons were so close together in the nucleus?
A particle he called the neutron also existed in the nucleus that helped to hold the protons together
How did Rutherford know that the nucleus of the atom was so small and so dense?
Since most of the alpha particles were able to go through the gold foil and only a few were deflected this result told him that most of the atom was mostly empty space, but since some of the atoms bounced back it had to
How did Rutherford disprove J.J Thomson's model?
He found that the positive part of an atom was not a "cloud" that alpha particles could pass through. He found that there was a solid, dense, positive core to the atom known as the nucleus that would deflect alpha parti
What is the mass of an electron according to J.J Thomson's research?
1/2000 the size of the smallest atom known, Hydrogen...0.000534 amu
What is JJ Thomson famous for discovering?
How do we know the particles in the nucleus have a positive charge?
Some of the positive alpha partices were deflected and repelled when they came near the nucleus
What was surprising about Rutherford's experiment?
The alpha particles did not just go straight through the gold foil, in fact some were deflected and even bounced back
Why doesn't the atomic nucleus fly apart from protons repelling each other?
The attractive strong nuclear force between neutrons and protons is much stronger than the repulsive electric force between protons
What is the "force" between protons and neutrons in the nucleus called?
strong nuclear force
Which particle explained the extra mass in an atom?
In Rutherford's Gold Foil experiment, why did the positive alpha particles bend away from the concentrated mass of protons in the middle of the atom?
like charges were repelled the nucleus
In Rutherford's Gold Foil experiment, what happened to the alpha particles when they came into contact with the concentrated mass of protons in the center of the atom?
they were defected
In Rutherford's experiment simulation, how did concentrating / compressing protons into the center of the atom change its electrical field?
It got stronger
What did the Plum Pudding model propose?
negative particles are spread out in a positive gel/soup/pudding substance
What instrument do scientists use to measure and observe an atom?
Positively charged particles with an amu of 1 and found in the nucleus
the particles of the nucleus that have no charge
Anything that has mass and takes up space
Matter is made up of tiny particles that are too small to be broken down into smaller pieces. Particles can also stick together in different combinations to make up materials. -Democritus
used the cathode ray tube to discover electrons
Plum Pudding Model
Found by the Cathode Ray experiment. He discovered electrons. From his high voltage electricity and how particles were attracted to a positive plate he knew there was a positive charge something. He believed there was a positive charged haze around negative charged objects for an atom. -J.J Thomson
a measurement/data/observations of one thing to get information regarding another.
Nuclear Model 1
Found protons and the nucleus by shooting alpha particles at a thin sheet of Gold. 1 out of every 10,000 shot back showing repelling. This proved a nucleus must be small and positive. Electrons must also be separate. -Rutherford
Nuclear Model 2
Rutherford believed there had to be another particle to account for the missing mass but could not find them. James Chadwick found them in 1932. He included them in this model.
taking direct measurements/data/observations on the data itself
Two objects with the same charge will
The amount of space an object takes up
All of the studying through time to gain knowledge of the atom is what type of observation?
Matter can be split indefinitely. The smaller piece will look identical to the larger piece. -Aristotle
Negatively charged particles found in the electron cloud
Two objects with different charges will
What are all materials made of?
Ernest Rutherford performed the Gold Foil Experiment where he shot alpha particles through a thin gold sheet and found that almost all but 1/10,000 were absorbed. This proves:
There is a small, dense, positive core in an atom that he named a nucleus. It was hard to hit because he only hit it once. This is because it is so small. The rest of the atom is mostly empty space.
Why did the majority of Rutherford's Alpha particles pass straight through the Gold sheet?
For Gold atoms (and any atom) there is a large area (volume) where electrons occupy called the electron cloud. This leaves lots of empty "space" from atom to atom.
We know that atoms exist even though they are so small that we cannot see them. J.J Thomson, Ernest Rutherford, and Neils Bohr performed experiments to gain observations regarding atoms to revise models of atoms.
When an atom or object gains electrons
It will have a negative charge
If an atom/objects loses electrons
It will have a positive charge
How does a neutral object become charged?
Through rubbing/friction with another object..this causes it to transfer electrons
YOU MIGHT ALSO LIKE...
Science Chapter 8 Atoms
Introduction to Atoms: Ch. 11
Physics: 4 Models of The Atom; Fundamental Sources
Atoms, Elements, And Periodic Table
OTHER SETS BY THIS CREATOR
Unit 1 Investigation 4
Unit 1 Investigation 3
Unit 1 Part 1 Test Review