Atomic Theory
Who coined the term “atomos”? What does it mean?
The atomic number is the same as the number of ____ in an atom
protons
What two components do you need to find the average atomic mass of an element?
mass number and percent abundance
Which subatomic particle has a negative charge?
electron
Where are many of the elements created?
stars
What did J.J. Thomson’s model of the atom look like?
Plum Pudding
How do you find the number of neutrons in a given isotope?
mass number - number of protons
Carbon has 3 naturally occurring isotopes: carbon-12, carbon-13, and carbon-14. If the average atomic mass of carbon is 12.011 amu, which isotope is the most abundant? How do you know?
Carbon 12. 12.011 is closest to 12, so the majority of carbon atoms are a carbon-12 isotope.
Where are each of the subatomic particles located?
protons and neutrons- nucleus
electrons- electron cloud
Through what process are elements created?
fusion
What was the problem with Bohr's model? How did Schrodinger fix it?
Bohr had fixed energy levels and electron placements; Schrodinger discovered the electron cloud
Define isotope
atoms with the same number of protons but a different number of neutrons
How is average atomic mass different from mass number?
average atomic mass: the average of the mass numbers for all isotopes of that element.
mass number: the mass (protons + neutrons) of that specific isotope
How many protons does Br have?
35
What is the heaviest element forged in a star's core?
iron
Name two conclusions of Rutherford's Gold Foil experiment
Small dense nucleus, positively charged nucleus, atom is mostly empty space
How many neutrons does Cadmium-113 have?
65
Write out the two common ways to express a carbon isotope that has a mass number of 13.
136C
Carbon-13
What subatomic particle(s) make up the majority of an atom's mass?
protons and neutrons
What can you infer about the age of a star if there is iron present?
it is near the end of its life
List the scientists who contributed to atomic theory in chronological order
Democritus, Dalton, Thompson, Rutherford, Bohr, Schrodinger
What is the mass number of a stable isotope with 82 electrons, 82 protons, and 126 neutrons?
208
Strontium consists of four isotopes with masses of 84 (abundance 0.50%), 86 (abundance of 9.9%), 87 (abundance of 7.0%), and 88 (abundance of 82.6%). Calculate the atomic mass of strontium.
87.712u
What is the atomic number for Rb? How many electrons does it have?
37, 37
What causes a star to become a supernova?
the core collapses because it runs out of fuel