Oh my word!

The unit test for chemical bonds was not as difficult as I expected because many of the questions on the test were similar to ones I studied on the practice quizzes on Schoology. I was (un)pleasantly surprised when Frankenberg revealed to us that there were 46 questions on the test. I was planning on there being less, but I didn't have much time to dwell on this because I had to get the test started! Even with so many questions, I was able to finish all of them and be fairly confident in 80% of my answers, which is above average for chemistry tests! I hope I will score as well as I felt after the test, and if not, I will not be too upset about it because this was a particularly challenging unit for me!

Hybridization, Lewis Structure, and Chemical Bonds Study Links

I used these study links to prepare for the test! Studying for the test was more stressful than usual because we didn't have a mid-unit quiz, so I did not know what to expect. Also, we had less time to digest the information this unit because of spring break coming up so soon.

Sigma and Pi Bonds, Hybridization Video

Crash Course Chemistry Lewis Structure Video

Tyler DeWitt Molecular Geometry Video

More Study Links:

Hybridization

Polarity Explanation

Molecular Geometry

Chemical Bonding Fun

This new unit, Chemical Bonding, is all about how atoms and molecules act when in chemical bonds. We have mostly been looking at covalent bonds this unit, and how to draw these molecules in different structures such as Lewis structures and 3-D geometry structures.

Ionic Bonds:

• Composed of a metal and nonmetal bonded to one another
• One atom in the resulting molecule has "stolen" the other atoms electrons

Covalent Bonds:

• Two nonmetals bonded together
• Share electrons

Lewis Structures:

• These structures show where the valence electrons are located on the molecule
• On this structure, since the F atoms need to have 8 electrons on their outermost valence shell to be stable, we added three non-bonding pairs of electrons (6 electrons) to the F valence shell.
• A correct Lewis structure always shows the correct number of bonds and non-bonding pairs of electrons on each atom

3-D Structure:

• 3-D has the same structure as Lewis structure, but instead we use a solid line and a dashed line to show that the molecule is 3 dimensional
• These different lines help show the three dimensions on a two dimension scale

Unit Test Reflection

This unit test was difficult in that there were more questions than normal. There were 50 questions, and I felt rushed by the end. I did not have enough time to finish the last problem comfortably so I had to guess, and that problem was especially difficult anyway. This unit, admittedly, was a little easier than acids and bases, but it was still challenging in that there was a lot of memorization involved in this unit. I'm excited to start something new and I am going for the best for this test grade!

                           

                           

Periodic Trends

Ionization energy- qualitatively defined as the amount of energy required to remove the most loosely bound electron of an isolated gaseous atom to form a cation

Electron affinity- neutral atom's likelihood of gaining an electron

Atomic radius- total distance from an atom’s nucleus to the outermost orbital of electron

Periodic trends all follow a set pattern with a few exceptions. Electron affinity and ionization energy both go up and to the right, while atomic radius goes down and to the left.

Resources:
Electron Affinity
Electron Affinity Khan Academy
Ionization Energy
Atomic Radius

Wavelength and Energy Calculations

Wavelength  is the distance between two crests on a wave. A longer wavelength means the wave has less energy and lower frequency, and a shorter wavelength means the wave has a higher frequency and energy.

Waves with higher frequency and energy are shown on the left side of the diagram while lower frequency and energy waves are shown on the right side.

The energy of a photonis found using this equation. If you were to be looking for the energy in a  mole, you would just have to multiply your number that you get for energy of a photon by Avogadro's number 6.02 x 10^23.

Periodic Trends and Electron Configuration Study Links

These are great videos for describing periodicity and electron configurations. Bozeman Science always makes the best study videos and I always refer to them when I am preparing for tests.

Periodicity Bozeman Science

Electron Configuration

Here are some extra study links that really helped me:

Periodic table and electron shells Khan Academy

Hund's Law

Aufbau Principle

Pauli Exclusion Principle