Atomic Structure
What subatomic particle determines an atoms properties?
The Proton
What is the major discovery that separated Thompson's Plum pudding model from Dalton's Atomic theory?
The discovery of subatomic particles, specifically, the electron
How many sig figs are in the number 101.0
4
What are the base metric units for volume, mass, and distance?
Liters, Grams, and Meters
An average atomic mass is calculated using two values of an element
Percent abundance and mass of each isotope
If an atom has 38 protons 36 electrons and 50 neutrons, what is the mass number and charge and identity of the atom?
Strontium, Sr-88, +2 Charge
What is meant by the term "ground state"?
The lowest energy level that an electron exists. The preferred/default energy level for an electron to exist
How many sig figs are in the number 4.21 x 1025
3 Sig Figs
Convert this number to scientific notation: 312000
3.12 x 105
How is the weighted average mass calculation different from a normal average calculation?
Weighted average mass takes into account the percent abundance of each isotope while a normal average calculation would not.
Where do negatively charged subatomic particles exist in an atoms structure? Be specific
Orbiting in Energy Levels/Orbitals
What is meant by the term "excited state"?
An energy level higher than the ground state that an electron will jump to after being energized.
How many sig figs should the product of this problem be?
9.824 x 6.4
2 sig figs
63
0.000619
Why is average atomic mass more important to include on the periodic table rather than individual masses of isotopes?
Because isolating isotopes within a sample is not realistic. Any given sample of any given substance will include all isotopes in some ration.
What is the difference between a Boron-10 and Boron-11 atom?
Boron-11 has one more neutron, Boron-10 has one fewer neutron
What did Rutherford's gold foil experiment conclude about the atom?
The atom is mostly empty space and has a dense positive center
How many sig figs should be recorded in the sum of the following problem?
16.45 + 3.1
3 digits
19.55 rounds into 20.0
What does the abbreviation amu stand for?
Atomic Mass Unit
Despite having the isotopes C-12, C-13, and C-14, why is carbons average atomic mass calculated to be 12.0108?
Because carbon-12 is far more abundant than either of the other two isotopes
Define an ion and describe how an atom might become an ion.
Any atom that gains a positive or negative charge by giving away or receiving an electron
What do Bohr's Model (Planetary Model) and the Quantum Mechanical model have in common?
Electrons orbit the nucleus in quantized energy levels.
How many sig figs should be in the quotient for the following problem:
25.67 / 13
2 Sig figs
1.9746 rounded to 2 sig figs is 2.0
How many grams would be in 2.5 kg?
2500 g
If an element has three naturally occurring isotopes with masses of 25.0 amu, 26.0 amu, and 27.0 amu, and their abundances are 20%, 50%, and 30% respectively, what is the element's average atomic mass? Is this likely to be a real element?
26.1 amu, no it is not likely to be a real element. The average being somewhere inbetween adjacent elements.