Unit 2 Reflection

       This unit was about the nature of matter, compounds, molecules, bonds, acids, bases, and pH. In response to the essential unit question, I believe that increasing molecular complexity serves as the building blocks for life by learning from the ground-up, starting with atoms, the basic unit of matter, and working your way up to compounds and molecules or the types of bonds. By learning these things in order, it gives us a better understanding of what we're really learning by starting small, instead of diving in head first.
        About the nature of matter, I learned that atoms are the basic unit of matter and make up everything we see and feel in this entire world, including all of us. Atoms are made up of three particles; protons, neutrons, and electrons. Protons have a positive charge and have the same mass as neutrons, neutrons have no charge/neutral charge, and electrons are negatively charged, and are 1/1840 size of a proton while always in constant motion. The nucleus is in the center of an atom, made up of protons and neutrons. I had no trouble remembering the charges of each of the particles, though I occasionally have trouble remembering what the nucleus is and what it's purpose is. Atoms are also the basic unit of elements, which are pure substances that are listed on the Periodic Table with their atomic number. The atomic number of an element never changes.
     I also learned that compounds and molecules are formed by two or more elements and have formulas, which are abbreviations of the number and types of atoms in a molecule (Ex: H20 = 2 hydrogens + 1 oxygen). I have trouble memorizing the different types of bonds, so I realize I have to work on that. Chemical bonds are the energy stored between atoms. There are three types of bonds; Ionic bonds, Covalent bonds, and Hydrogen bonds. Ionic bonds form when an atom gains or loses an electron, covalent bonds are electrons shared between atoms and could have double or triple bonds, and while hydrogen bonds are not as strong as covalent or ionic bonds, they are able to hold molecules together due to slight attraction of positive to negative charged regions. I had a lot of difficulty memorizing the types of bonds and their purposes, so I'm going to keep working on that.
      We learned why water is wet by first going over the properties of water. One of it's properties, polar is the unequal distribution of charge between H and O. It has the ability to form multiple H-bonds, is the most abundant molecule in most living organisms, is less dense when frozen, and has high specific heat - absorbs a great deal of energy.
     I learned that pH is the measurement of hydrogen ions in solutions. I was also taught about the pH scale, 7=neutral, anything larger than 7 is acidic, and anything less than 7 is basic. I might have trouble remembering the scale, so I'm going to study that some more.