Activity #2

Activity #2- Atoms and Atomic Structure

(Questions 1-2)

This image shows the Hydrogen atom in its ground state. I chose this element because it has an equal amount of electrons and protons. The Periodic symbol for Hydrogen is "H". The common household item I used to represent the proton is a small ball of play dough, and the nucleus is represented with a tinker toy.

Atomic Number: 1

Atomic Mass: 1.0079

This image shows the element Oxygen in its ground state. The Periodic Table uses the letter "O" to represent Oxygen. I chose this element because of its various powerful compounds that can be helpful or harmful (such as breathing air or carbon monoxide). The tinker toy in the center of the image represents the nucleus of the atom, and the surrounding electrons and protons are show with small balls of play dough.

Atomic Number: 8

Atomic Mass: 15.9994

This image shows the element Magnesium in its ground state. I chose this element because, like Hydrogen, it has an equal number of protons and electrons. On the Periodic Table Magnesium is represented with the letter "M". I have used a tinker toy to illustrate the nucleus of the atom, and small balls of play dough to show the protons and electrons.

Atomic Number: 12

Atomic Mass: 23.305

3. In your models, which two subatomic particles are equal in number?
ANSWER:
The proton and neutron are equal in number.

4. How would you make an isotope for one of your models?  What would change with the model?
ANSWER:
The number of neutrons would change according to the element, but the proton and electron amounts would remain the same.

5. Considering the overall volume of your element models, what makes up most of the volume of an atom?
ANSWER:
The electrons take up the majority of the volume in the atom. The space between layers of the atom is mainly empty.

6. For one of your models, show with another image what happens when energy excites an electron.

This an image of Hydrogen in its excited state. Notice that the proton has moved to an outer layer, further from the nucleus.

7. Once the electron is excited, what do we typically observe when the electron returns to the ground-state? 

ANSWER: When an electron is in an excited state, it returns to the lower energy state. The excited state of the electron emits a photon of energy, which may be observed as light. (Think fireworks!)

8. Why are some elements different colors when they are excited? Hint: when electrons are excited (by something like heat from an explosive) they move up to another orbital and when they fall back they release the energy in the form of light. 
ANSWER:  According to the Bohr Model, the arrangement of electrons when they're excited can produce different colors in different elements. When an electron returns to the the lower energy state after becoming excited, it emits a photon of energy that can be observed as light.

9. With the Fourth of July coming up quickly, explain how the colors of fireworks arise.

ANSWER:  The Bohr Model explains the arrangement of electrons and also the reasoning for the colors seen with fireworks. The Line Spectra explanation states that when a light from a gaseous substance is passed through a prism, it produces a line spectrum. In addition, the Continuous Spectra reasons that when light emitted from a solid substance is passed through a prism, it produces continuous spectrum of colors.

  

10.  Explain the overall organizational structure of the periodic table.

ANSWER:  In 1869, Dmitri Mendeleev arranged the elements in order of increasing atomic mass. He specifically left gaps for undiscovered elements. Additionally, he was able to predict the properties of those elements. Amazingly, Mendeleev's predictions were later found to be accurate!

11. List two example elements for each of these groups or classes: Alkali Metals, Alkaline Earth, Halogens, Noble Gases, Transition Metals, Non-Metals, and Metalloids.

ANSWER: 

Alkali Metals Examples: Lithium (Li) and Sodium (Na)

Alkaline Earth Examples: Calcium (Ca) and Barium (Ba)

Halogen Examples: Fluorine (F) and Chlorine (Cl)

Noble Gases Examples: Helium (He) and Neon (Ne)

Transition Metals Examples: Titanium (Ti) and Silver (Ag)

Non-Metals Examples: Xenon (Xe) and Hydrogen (H)

Metalliods Examples: Boron (B) and Arsenic (As)