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Name/describe the location of each of the subatomic particles.
Protons and Neutrons are found in the Nucleus.
Electrons are found at a distance from the nucleus in orbitals.
If you know the number of electrons in an atom, you know the number of ________________ in an atom.
Protons
What mathematical combination of subatomic particles creates the mass number of an element?
Protons + Neutrons
Which key figure coined the term "atomos" to describe the indivisible particles that made up matter?
Democritus
What did Aristotle believe matter was made up of?
The four elements; fire, water, air, and earth
What TWO things create an isotope's unique identifier?
The name of the element + the mass number
Explain the Law of Electrostatic Charges.
Opposite electrical charges attract
Which scientist experimented with a Crooke's Tube and created a "cathode ray" which eventually led to the discovery of the electron?
Dalton
Which model proposed that the newly discovered electrons were spread out and embedded in a positive substance?
Plum Pudding model
Potassium-33, Potassium-24, and Potassium-40 are all isotopes.
With only regarding their subatomic particles, what do they have in common AND how are they different?
Same number of protons but different number of neutrons
Describe TWO ways atoms of an element can be different from one another? (HINT: think about subatomic particles)
Isotopes: different number of neutrons
Ions: different number of electrons
Explain the difference between ATOMIC MASS and MASS NUMBER.
Atomic mass: average mass of all isotopes of an element
Mass number: protons + neutrons
Rutherford's gold foil experiment resulted in two observations:
1. Atoms are mostly _______________
2. Atoms have a ______________ center in the middle called a _______________.
EMPTY SPACE
POSITIVE, NUCLEUS
Describe the movement of electrons according to the Bohr model.
Electrons move around the nucleus at fixed distances in energy levels rather than randomly about the center.
Describe what has happened to the number of electrons according to the isotope notation.
Kr+8
The atom had lost 8 electrons
Why can the atomic mass be a decimal but the number of subatomic particles be only whole numbers?
The atomic mass is an average of decimals.
Subatomic particles are singular and cannot exist in portions, parts, or halves.
According to the BOHR MODEL, if an electron were to fall to a lower energy level, the energy would be lost in the form of ________.
light
According to your textbook, Quantum Mechanics was a new form of physics that observed what?
The behavior of matter and energy at the atomic and subatomic levels.
Why do you suppose neutrons were the last of the subatomic particles to be discovered?
Due to their lack of an electrical charge, they were hard to detect
Sulfur has FOUR naturally occurring and stable isotopes: Sulfur-32, Sulfur-33, Sulfur-34, and Sulfur-36.
Sulfur has an atomic mass of 32.06. Which isotope is the most abundant and why?
Sulfur-32 due to the atomic mass being numerically closer to 32.06 than the others.
Name THREE out of the FIVE observations made by Dalton according to our textbook.
1. Elements are made of atoms
2. Atoms are indivisible and cannot be destroyed
3. The atoms of an element are all alike
4. The atoms of one element are different from the atoms of another element
5. Atoms combine chemically in small, whole number ratios
Explain the difference in regards to the movement/location of electrons between the BOHR MODEL and the QUANTUM MECHANICAL MODEL.
The Bohr model explained that electrons orbited around the nucleus on fixed paths away from the nucleus.
The QM model saw that electrons inhabited oddly shaped regions called orbitals where they are likely to be found.
Why is it more proper to describe the QUANTUM MECHANICAL MODEL as "workable" rather than correct?
It explains current observations about atoms though at some point in the future they can be updated or even replaced with new information.
Regarding his discovery of the nucleus, Rutherford said "it was almost as incredible as if you fired 15-inch artillery shell at a piece of paper and it came back and hit you".
Why do you think he said that?
He expected the alpha particles to pass through the atoms with ease; however, some bounced back due to hitting the positively dense centers or nuclei.
The following is a breakdown of the subatomic particles for Gold (Au):
Protons: 79 Neutrons: 118 Electrons: 79
Create a chart or illustration showing both an ANION and a CATION of Gold + ION NOTATION for each.
CATION or Au+
Protons: 79, Neutrons: 118: Electrons: n<79
Anion or Au-
Protons: 79, Neutrons: 118, Electrons: n>79