Atomic Structure
0.0467
4.67%
2nd rule
All atoms of a given element are identical, but they differ from those of any other element.
13
Aluminum is an ion with a mass number of 27, 13 protons, 14 neutrons, 10 electrons, and a +3 charge. What is the atomic number?
33
Arsenic is neutral with a mass number of 75, 33 protons, 42 neutrons, 33 electrons, and 0 charge. What is the atomic number?
B-11
Atomic mass is 10.81 AMU. Is B-10 or B-11 more abundant?
51.83%
Atomic mass is 107.96 AMU. 48.17% of Ag-109. What percentage of Ag-107?
35%
Atomic mass is 187.55 AMU. 5% of Hf-176. 19% of Hf-177. 27% of Hf-178. 14% of Hf-179. What percentage of Hf-180?
92.21%
Atomic mass is 28.11 AMU. 4.7% of Si-29. 3.09% of Si-30. What percentage of Si-28?
78.68%
Atomic mass is 39.02 AMU. 9.67% of X-38. 11.34% of X-40. 0.31% of X-41. What percentage of X-39?
93.12%
Atomic mass is 39.14 AMU. 6.88% of Potassium-41. What percentage of Potassium-39?
92.5%
Atomic mass is 6.93 AMU. 7.5% of Li-6. What percentage of Li-7?
6.09 AMU
Atomic mass is 6.941 AMU. 93.5% of Lithium-7. What is the mass of the other isotope?
69.1%
Atomic mass is 63.62 AMU. 30.9% of Copper-65. What percentage of Copper-63?
1 AMU
Atomic mass of protons and neutrons
Dalton and Rutherford
Atoms are building blocks, extreme similarity, atomic mass
Dalton
Atoms are indestructable, no subatomic particles
3rd rule
Atoms are neither created nor destroyed in any chemical reaction.
Rutherford
Atoms have subatomic particles, mostly empty. Protons, neutrons, electrons. Varying neutrons.
Isotope
Atoms of the same element that have different number of neutrons
2
Helium is neutral with a mass number of 4, 2 protons, 2 neutrons, 2 electrons, and 0 charge. What is the atomic number?
12
How many electrons are in a neutral atom of magnesium (12 protons)?
18
How many neutrons are in an atom of an mass number of 35 (17 protons)?
16
How many neutrons does Phosphorous-31 have (15 protons)?
28
How many protons are in a Nickel-58 atom (30 neutrons)?
1
Hydrogen is neutral with a mass number of 2, 1 proton, 1 neutron, 1 electron, and 0 charge. What is the atomic number?
Democritus
In 450 BC, he proposed that all matter is actually composed of tiny, indivisible particles. Other philosophers of that time (Aristotle) didn't agree with his ideas.
Protons = electrons
In a neutral atom...
53
Iodine is an ion with a mass number of 127, 53 protons, 74 neutrons, 54 electrons, and a -1 charge. What is the atomic number?
John Dalton
James Prescott Joule was a student of his. Concluded that the properties of matter could be explained in terms of atoms. His atomic theory of matter (1803) was based on 4 postulates
36
Krypton is neutral with a mass number of 84, 36 protons, 48 neutrons, 36 electrons, and 0 charge. What is the atomic number?
Atomic number - net charge
# of electrons
1/1000
The nucleus's size compared to the rest of the atom
0.08
8%
0.8376
83.76%
X-39
9.67% of X-38. 78.68% of X-39. 11.34% of X-40. 0.31% of X-41. What isotope is most common?
0.9
90%
20.2 AMU
90% of Ne-20. 10% of Ne-22. What is the atomic mass?
20.19 AMU
90.48% of Neon-20. 0.27% of Neon-21. 9.25% of Neon-22. What is the atomic mass?
28.11 AMU
92.23% of Silicon-28. 4.67% of Silicon-29. 3.1% of Silicon-30. What is the atomic mass?
1/1834 AMU
Atomic mass of electrons
Atomic number
# of protons
Atomic mass - atomic number
# of neutrons
1.00
100%
10.8 AMU
19.9% of Boron-10. 80.1& of Boron-11. What is the atomic mass?
0.25
25%
4th rule
A given compound always has the same relative numbers and kinds of atoms.
Ernest Rutherford
A student of JJ Thompson's, who proved that an atom was much more than just empty space and scattered electrons, an atom must have a positively charged center, and the nucleus is small.
56
Barium is an ion with a mass number of 137, 56 protons, 81 neutrons, 54 electrons, and a +2 charge. What is the atomic number?
Joseph John Thompson
Beginning in 1896, he conducted several experiments. He did not compute the mass of an electron, but he did determine the ratio of an electron's charge to its mass.
5
Boron is neutral with a mass number of 10, 5 protons, 5 neutrons, 5 electrons, and 0 charge. What is the atomic number?
35
Bromine is an ion with a mass number of 80, 35 protons, 45 neutrons, 36 electrons, and -1 charge. What is the atomic number?
6
Carbon is neutral with a mass number of 12, 6 protons, 6 neutrons, 6 electrons, and a 0 charge. What is the atomic number?
Manhattan
Chadwick led the British team in this project
Neutral
Chlorine has an atomic number of 17, mass number 35, 17 protons, 18 neutrons ,17 electrons, and 0 charge. Is the element an ion or neutral?
29
Copper is an ion with a mass number of 65, 29 protons, 36 neutrons, 27 electrons, and a +2 charge. What is the atomic number?
1932
Date that Chadwick discovered the neutron
1803
Date that Dalton created the Atomic Theory of Matter
1913
Date that Moseley discovered the proton
1909
Date that Rutherford discovered the nucleus, gold foil experiment, and nuclear atom model
1896
Date that Thompson discovered the electron and plum pudding model
Atomos
Democritus named these tiny particles these.
Unique mass number
Each element has a...
1st rule
Each element is composed of extremely small particles called atoms.
9
Flourine is an ion with a mass number of 19, 9 protons, 10 neutrons, 10 electrons, and -1 charge. What is the atomic number?
79
Gold is an ion with a mass number of 197, 79 protons, 118 neutrons, 78 electrons, and a +1 charge. What is the atomic number?
Robert Millikan
He determined the charge of an atom using his experiments and the electron's charge to mass ratio from Thomas's work.
Ion
Magnesium has an atomic number 12, mass number 24, 12 protons, 12 neutrons, 10 electrons, and charge of +2. Is the element an ion or neutral?
25
Manganese is an ion with a mass number of 35, 25 protons, 30 neutrons, 22 electrons, and +3 charge. What is the atomic number?
1.674929x10-27
Mass (KG) of a proton or neutron
9.109390x10-31
Mass (KG) of an electron
Oil droplets
Millikan dropped these between electronically charged plates.
9.11X10-28 AMU
Millikan's calculated mass of an electron
30
Mn has an atomic mass of 55 AMU. 25 protons. How many neutrons?
Plum Pudding Model
Name of Thompson's atomic structure
Electron
Negative charge, 0 AMU, shell location
10
Neon is neutral with a mass number of 20, 10 protons, 10 neutrons, 10 electrons, and 0 charge. What is the atomic number?
0
Net charge of a neutral atom
Neutron
Neutral charge, 1 AMU, nucleus location
Atomic Number
Number of protons in the nucleus of each element
Nucleus
Once the positively charged proton was discovered and to be located in here, it was found that protons could only account for about half of the observed mass of it.
8
Oxygen is an ion with a mass number of 16, 8 protons, 8 neutrons, 10 electrons, and -2 charge. What is the atomic number?
Subatomic particles
Particles in the nucleus of an atom
99%
Percent of the mass that the nucleus takes up
15
Phosphorous is an ion with a mass number of 30, 15 protons, 15 neutrons, 18 electrons, and -3 charge. What is the atomic number?
Proton
Positive charge, 1 AMU, nucleus location
Postulate 2
Postulate of Dalton's atomic theory of matter that is not entirely true
19
Potassium is an ion with a mass number of 39, 19 protons, 20 neutrons, 18 electrons, and a charge of +1. What is the atomic number?
119
Pt has an atomic mass of 197 AMU. 78 protons. How many neutrons?
Gold foil
Rutherford used this experiment to prove the plum pudding model wrong, and discover the nucleus of the atom.
14
Silicon is an ion with a mass number of 28, 14 protons, 14 neutrons, 14 electrons, and 0 charge. What is the atomic number?
20
Sodium is an ion with a mass number of 32, 20 protons, 12 neutrons, 19 electrons, and +1 charge. What is the atomic number?
Hans Geiger
Student of Rutherford, created the Geiger Counter which detected and measured radiation
Henry Moseley
Student of Rutherford, found that atoms of each element contain a unique positive charge in the nucleus, and therefore an atom's identity comes from the number of protons in its nucleus.
James Chadwick
Student of Rutherford, spent time studying in Berlin, Germany and worked in Hans Geiger's lab, discovered the neutron, which has about the same mass as a proton
The element
The number of protons in the nucleus defines...
Atom
The smallest amount of an element. The smallest particle of an element that retains the chemical identity of that element.
Atomic Mass Unit
The unit of mass at the atomic level
Atomic Mass
The weighted average of the mass numbers of all the element's isotopes
Cathode ray tubes
Thomas used these to discover the atomic structure
50
Tin is neutral with a mass number of 118, 50 protons, 68 neutrons, 50 electrons, and charge 0. What is the atomic number?
Mass number, percent abundance
To calculate atomic mass, multiply the __________ of each isotope by its __________ expressed as a decimal
Mass Number
Total number of protons and neutrons in an atom
Phosphorous-31
What is the isotope name for an atom of an element with 15 protons, 15 electrons, and 16 neutrons (Phosphorous)?
Potassium-39
What is the isotope name of an element with 19 protons, 20 neutrons, 19 electrons (Potassium)?
Potassium-40
What is the isotope name of an element with 19 protons, 21 neutrons, and 19 electrons (Potassium)?
Potassium-41
What is the isotope name of an element with 19 protons, 22 neutrons, and 19 electrons (Potassium)?
Carbon-13
What is the isotope name of an element with 6 protons, 7 neutrons, and 6 electrons (Carbon)?
Nitrogen-15
What is the isotope name of an element with 7 protons, 8 neutrons, and 7 electrons (Nitrogen)?
None
What is the most common isotope of an element with an atomic number of 2 and an atomic mass of 4
30 neutrons
What is the most common isotope of an element with an atomic number of 26 and an atomic mass of 56?
9 Neutrons
What is the most common isotope of an element with an atomic number of 8 and an isotope of 17?
Hydrogen-3
What is the name of an isotope of an element with 1 proton, 2 neutrons, and 1 electron (Hydrogen)?
Calcium-40
What is the name of an isotope of an element with 20 protons, 20 neutrons, and 20 electrons (Calcium)?
Iron-56
What is the name of an isotope of an element with 26 protons, 30 neutrons, and 26 electrons (Iron)?
Selenium-78
What is the name of an isotope of an element with 34 protons, 44 neutrons, and 34 electrons (Selenium)?
Uranium-238
What is the name of an isotope of an element with 92 protons, 146 neutrons, and 92 electrons (Uranium)?
Small number percentage
What to look out for when calculating atomic mass