Chemistry, more like cheMYSTERY to me! – Democritus | The Model So Far
Inorganic chemistry - The study of all other elements of non-living matter. 3. The quantitative aspects of the physical properties of substances and their relationship to chemical structure and composition. CHEMystery: Acids and Bases. University of Alberta: Introductory Chemistry I - Atoms and Molecules: Periodic of Chemistry - Relationship Between Energy And Matter · CHEMystery: Energy. Elements (or more properly, atoms) are symbolized by either one, two, All matter is a massive collection of relax-sakura.infoles are a joining of two or more.
Matter consists of definite particles called atoms. In chemical reactions, the atoms rearrange but they do not themselves break apart. The atoms of one particular element are all identical in mass and other properties.
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When atoms of different elements combine to form compounds, new and more complex particles form. However, in a given compound the constituent atoms are always present in the same fixed numerical ratio. This theory is not perfectly correct. We now know that atoms can be broken into smaller pieces see Nuclear Reactions and most elements occur as mixtures of two or more isotopes atoms of an element with slightly different masses.
Modern Atomic Theory It has been found that atoms are also made up of three subatomic particles--protons, neutrons, and electrons. The atom has a nucleus made up of protons and neutrons with electrons "orbiting" around it. The internal structure of the atom allows us to understand its properties. Because protons and neutrons are in the nucleus, they are sometimes collectively called nucleons. Protons have a mass of approximately 1 atomic mass unit amu I start all of chemistry with the above story about Democritus and tell my students that this is our current model of the atom because we do not have any other evidence to tell us otherwise.
Then I do the exploding can demonstration because chemistry is all about blowing things up, right? Exploding Can Demo The exploding can demonstration helps establish the practice of drawing particle diagrams.
Students are asked to draw a particle diagram before the can is lit, while the can it lit, and when the can explodes. They come up with all sorts of explanations with their particle diagrams.
Chemistry, more like cheMYSTERY to me! – Democritus
Sometimes they are dead on, sometimes not. The right answer is not as important as the discussion of particles. The 4 I always have them come up with are: I do not tell students how the exploding can works here because they do not have the background knowledge to fully appreciate the chemistry.The Mystery of Matter: “INTO THE ATOM” (Documentary)
Instead I bring it back on the last day of class and have the students try to explain it again with their more robust model of the atom. I have edited the lab so it is not exactly the same as what is in the Modeling Instruction materials but it includes a variety of chemical and physical changes that gain, lose and keep the same mass depending on how you define the system. After every group has collected their data, I have the class compile their data on the main board in the class.
Each group writes whether the experiment gained or lost mass and if so, how much? The data will not be perfect. You can usually spot which groups forgot to account for the mass of a test tube or beaker and use it as an opportunity to talk about sources of error.
Once we have established the mass change for each experiment, we whiteboard a before and after particle diagram for each mini experiment. There are two major kinds of substances: Elements - A substance that cannot be decomposed into two or more other substances by means of a chemical change is called an element.
An element consists entirely of atoms with the same atomic number.
CHEMystery: Atoms and Molecules: Dalton's Atomic Theory
Over one hundred and tentative different elements are known to exist. Most are metals such as mercury, iron, lead, copper, silver and gold.
Others are nonmetals such as oxygen, sulfur, iodine and neon. Still others are semi-metals metalloids such as silicon beryllium and boron.
Compounds - A substance that can be decomposed into other substances by a chemical reaction is a compound.