Tutor profile: Amy S.
Subject: Basic Chemistry
What is a valence electron?
A valence electron are the electrons of an atom that are the furthest away from the nucleus or center of the atom. Valence electrons are located on the "outer shell" of an atom. An atoms reactivity (ability to bond with other atoms) depends on how many valence electrons it has, because all atoms want a full outer shell (this is typically 8 electrons, with a few exceptions). So atoms will donate, accept or share electrons, in order to stabilize their outer shells. This is how reactivity occurs and molecules/compounds are formed.
What is DNA and what does it do?
DNA is a molecule in our bodies that acts as a recipe book of sorts. This "recipe book" is present in all of our cells and the "recipes" in DNA are called genes. Each gene can be read like a recipe to make things in our body called proteins (which would be the meal that you make). Those proteins are then used in your cells and all over your body to do things. An example of a protein would be insulin. When you eat, foods trigger genes (in DNA) of your pancreas cells to produce insulin. Insulin is then released into your blood to help sugar from food (called glucose) to get into your body cells, where it can be used by your cells to make energy.
Subject: Physical Science
How do the subjects in the Physical Sciences (Astronomy, Chemistry, Earth Science and Physics) relate to one another?
The Physical Sciences encompass our understanding of the laws that govern our universe and the bodies in it, as well as the history of the universe, from the beginning of time as we know it to when chemistry becomes biology (life emerges). The way that I approach physical science is in a narrative kind of format, so that it makes it easier to understand how complex abstract ideas fit together to create a story. Therefore, I don't teach a subject like Chemistry in isolation, but instead I explain matter and chemical reactions and behavior as it pertains to the rest of the universe. Most atoms were created in stars through a process called nucleosynthesis. They act in predictable ways as their environment cools, based on their make up, and those predictable reactions lead to more and more complex structures, within our universe like planets, and eventually life.
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