Blog Post 3

Blog Post 3 (Unit 3)

1. Describe the history of the atomic model.

To begin with, the atom was seen as a minuscule, indivisible object, typically viewed as being round, and with no internal components. This model was developed by Democritus. After this, it was discovered that atoms possessed negative and positively charged particles within them. This lead to the discovery of protons, and electrons. The nucleus of the atom was eventually concluded to be composed of neutrons and electrons, neutrons being discovered by bombarding the atomic structure with alpha particles. These bounced back, and returned in the direction in which they were launched, proving that there was yet another structure inside the atom. 

1. Explain each subatomic particle including their charge, relative mass, and locations in the atom.

Neutron - Neutrons are neutral, or uncharged subatomic particles occupying the nucleus of the atom. They are the same size as Protons and are 2,000 times larger than the size of an electron.  

Proton - Protons are positively charged subatomic particles placed within the nucleus of the atom alongside the Neutrons. They are the same size of Neutrons and are 2,000 times larger than electrons. The amount of electrical charge possessed by Protons is the same as the amount of electrical charge possessed by Electrons. 

Electron - Electrons negatively charged subatomic particles, located in orbitals around the nucleus of the atom. There are several different orbitals, filled according to how many electrons the atom possessed. Electrons are 2,000 times smaller than 

1. What was Mendeleev’s major contribution to chemistry?

Mendeleev is credited with ordering the elements, in a way nearly accurate to their placement today.  Laying out cards that illustrated the element's properties, and arranging them in such a way that they fit together, is the same method used to organize the periodic table of elements as we see it today. He was the first to try and order them in such a way, and was even able to find spaces, where an undiscovered element would have fit. 

1. Draw and upload a picture of a Bohr model of Gold (yes draw this one, not download a picture).

Electrons: 79

Protons: 79

Neutrons: 118

Energy levels: 6

1. Relate the numbers of the subatomic particles to the atomic number and mass number (use examples).

As one moves through the periodic table, it can be seen that from one element to the next, the atomic mass of the element increases alongside the atomic number of the element. This is what allowed Mendeleev to gain the basis of organization for his periodic table. 

1. Relate the numbers of the subatomic particles to the charge (use examples).

The more protons contained within an atom/isotope, the more positively charged the particle will become. The loss of electrons can also change the charge of the particle, just as the gain of electrons, causes the element to become negatively charged. Noble gasses, have even, and completed outer electron orbitals, resulting in a non-reactive state between them, and even other known elements. The loss, or gain of electrons, changing the charge, and completed status of the valence electron shell, results in the chemical reactions, and chemical bonds seen between elements. 

1. Define atomic mass and use isotopic abundance to calculate. (ex. explain how to find the average mass of Magnesium).

Atomic mass - The average atomic mass of an element is found through the measurement, and averaging of all its isotopic components. Different isotopes are found in different percentages of abundance, thus changing the resulting atomic mass greatly, depending on which is in higher concentration. 

1. Include your calculation for finding the isotope of pennies and identify how many pre-1982 pennies and how many post-1982 pennies were in your unknown container.

x = old pennies

[x(3.1) 10-x(2.5) = 27.26 ] = 2.26 (x = 3.77) 3.77 pennies (4) 

4 Old pennies, and 6 New pennies. Therefore 40% old pennies, and 60% new pennies composed the mixture.