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NOTES: Geochemistry (3.1-3.3, 21.3). The basic parts of an atom are:. Protons —In the nucleus, positive charge, has mass Neutrons —In the nucleus between protons, no charge, has mass Electrons —spin around the nucleus, negative charge, has no mass
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The basic parts of an atom are: • Protons—In the nucleus, positive charge, has mass • Neutrons—In the nucleus between protons, no charge, has mass • Electrons—spin around the nucleus, negative charge, has no mass • Orbital --(shell, energy level, cloud)– areas of space or path that electrons travel in
Electron orbitals are not really flat and circular They are regions of space that an electron with a certain amount of energy is likely to be found in at a given time.
Atomic Number • The number of both protons and electrons in an atom. • Protons and neutrons weigh about the same • Electrons hardly have any weight at all
Atomic Mass • This number is The weight(mass) of all 3 particles together. • You can estimate the number of neutrons by: Atomic mass – Atomic # ( bottom – top ) 12.0107 – 6 = 6.0107
Look at the number of neutrons for Carbon. What did we get? • The reason you got a decimal, is because it is the average of the # of neutrons over time = ISOTOPE • Neutrons get old, decay, and break down into smaller particles • Every moment in time, there could be a group of atoms that all have different neutron numbers flying around, because they’re all different ages!
The speed of decay of neutrons and other atomic particles allows us to find the age of rocks and fossils
Here are 3 isotopes of Lithium. What do they all have in common? What is different? Why?
PRACTICE: Find the number of Protons, Electrons, and, estimate the number of Neutrons for this element:
ELEMENTS ARE: Substances that cannot be decomposed or broken down naturally. Made up of only one kind of atom Elements can also have any number of atoms as long as they’re the same [ex. Carbon(C6), Oxygen(O2), Helium(He)]
Chemistry of the Earth’s Crust will tell you which elements appear the most in rocks and minerals:. . .
A molecule is just two or more atoms. . . They can be the same, or different.
Compounds • Molecules formed by a combination of two or more different elements This is a chemical FORMULA