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20 Cards in this Set
- Front
- Back
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What is an atom?
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Particles that are the basic building blocks for life.
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Atomic Structure is Comprised of 3 subatomic particles:
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Protons – have a positive charge and are found in the nucleus. The # of protons in an atom is the atomic#.
Neutron – neutral charge. Found in nucleus. Electrons – negative charge. Usually the same number as the protons. Move around the nucleus in orbitals. |
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What is an Element?
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Elements are pure substances with atoms with the same number of protons. If you have two atoms with same atomic number, they are the same element.
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What is the Periodic table of elements?
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Periodic table of elements – elements are arranged based on atomic #. The first 94 elements are naturally occurring. The rest are manmade.
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What are Isotopes?
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Isotopes – variations of an element. You have same number of protons, but the number of neutrons varies.
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What are Radioisotopes?
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Radioisotopes – radioactive isotopes, emit an electrical charge as their nucleus breaks down. May also emit subatomic particles.
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What is radioactive decay?
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Decay = process by which the nucleus breaks down. Decay is a stable process where outside variables do not affect it, e.g. temperature. Decay occurs at a constant rate.
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What is half-life?
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Half-life – amount of time for half of the radioactive isotope to decay. It decays into another isotope that is stable. Some are quick, and some are slow.
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Where do electrons travel?
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Electrons travel in orbitals. Orbitals are paths. The paths are not necessarily round. Orbits occupy shells. Within the shell, there are only certain paths the electrons can travel in.
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What are ions?
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Ions are electrically charged atoms.
Ions are negative, they have more electrons. Ions are positive, they have more protons. |
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What is a Molecule?
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Molecule = 2 or more atoms bond together by electrons interacting.
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What is a compound?
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Compound = two or more different elements where the relative percentages of each do not vary. E.g. water. Always have 2 H and 1 O
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What is a mixture?
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Mixture = 2 or more elements that intermingle, and the proportions do vary. This is different than a compound because the elements do not bond together. Instead, they may dissolve. Ex- glucose or sucrose in water (solution).
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What are 3 common types of bonds?
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Ionic bond - Hydrogen bond Covalent bond
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Why is water essential to life?
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Body is mostly composed of water and need water to maintain it. Water’s life-giving properties. Principle solvent in living things. Water helps maintain a stable temperature
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What is Hydrophilic?
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Hydrophilic=water soluble
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What is Hydrophobic?
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Hydrophobic=water insoluble
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What are Acids?
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Acids are proton donors. Acids are substances that dissociate in solutions to yield hydrogen ions Acidic solutions should have a higher hydrogen ion concentration than a basic solution. Weak acids and weak bases can be used for buffers.
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What are bases?
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Bases are proton acceptors. Bases dissociate in a solution to yield hydroxide ions. So, bases have a lower hydrogen ion concentration than hydroxide ion concentration. pH scale measures if a substance is acidic, basic, or neutral. Buffers minimize pH change. Weak acids and weak bases can be used for buffers.
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What kind of shape do atoms and molecules have?
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Atoms and molecules have 3-dimensional shape; Shape = function
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