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Cards In This Set
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Distinguish between an atom, isotope, ion element and molecule.
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Atom- smallest unit of and element
Isotope- atom with different # of neutrons Ion- atom or molecule that has lost or gained one or more electrons. Element- pure substance containing only on kind of atom. Molecule- two or more atoms bonded together. |
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Describe relative sizes of protons, neutrons, and electrons. Where is each found in an atom?
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Protons and neutrons are the same size and their total equals the entire atomic mass.
Electrons are tiny, so tiny they don't contribute to the atomic mass at all. Electrons are found in the outside ring. Protons and neutrons are found inside the nucleus. |
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Give the electrical charge of an atom, proton, neutron, electron, and of atoms that have gained or lost electrons.
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Proton- positive
Neutron- neutral Electron- negative Electron lost- Positive Electron gained- negative |
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List eh 13 most common element in living things.
Which are usually found in covalent bonds? Which are usually positive and negative ions? |
MgKcaFeINaCL.
CHOPN and/ or S Positive: mg+2, K+, Ca+2, Fe+2, Na+ Negative:I-, CL- |
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Distinguish between covalent, ionic, and hydrogen bonds.
Describe the structure of each. Explain their relative strength. Give and recognize examples. |
Covalent- Strongest.(indicated by a "-" between atoms) Share electrons.
Ex: H-OH Ionic- like a magnet. Positive ions attract to a negative ions. Ex: Na+CL- Hydrogen- Weakest. (shown by dotted line). attraction between the s- end of one polar molecule and the s+ end of another polar molecule. Ex: '...water molecules |
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Distinguish between polar and nonpolar covalent bonds.
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Polar covalent bonds has one or more polar covalent bonds. ( electrons are shared unequally between the 2 atoms).
Nonpolar covalent bonds has only regular nonpolar covalent bonds. ( electrons are shared equally between the 2 atoms). |
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Distinguish between and give examples of hydrophilic and hydrophobic molecules.
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Hydrophilic- water loving (salt)
Hydrophobic- water-hating/fear (oil) |
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Recognize products and reactants in a chemical reaction.
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Products- produce chemicals
reactants- required for reaction to occur |
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Draw several water molecules connected by hydrogen bonds.
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H-O-H . . .O-H
: l H-O-H H |
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What two aspects of water make life possible?
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Polar molecules and hydrogen bonds.
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Explain the water properties: Solvent
Ice Floats Evaporation, Freezing/Melting, and Heat Capacity Cohesion, Adhesion and Surface Tension Tell why each is important to life |
Solvent- dissolves liquid ( liquid water can transport these molecules)
Ice Floats- Rigid hydrogen bods in ice make it less dense than liquid water. ( Lakes and rivers would freeze solid) Evaporation- absorbs and heat above. ( helps cool organisms/ keep body at stable temp.). Freezing- releases energy (keep remaining water at a stable temp.). Melting- absorbs energy (keep remaining water at a stable temp.) Heat capacity- water, requires a lot of energy to heat up compared to other molecules ( Keeps body temp. constant, keeps aquatic habitat temps. constant, keeps coasts and humid climates more constant). Cohesion- water molecules stick to other water molecules by hydrogen bonds(Helps water move through plants and body fluid through capillaries). Adhesion- water molecules stick to other polar or charged solids(keeps water from being pulled back down the tree by gravity and keeps internal body surfaces moist). Surface Tension- Cohesion between water molecules creates tension at surface ( allows insects to walk on water). |
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What does pH measure?
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Acidity and concentration of ions.
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Give pH values for acid, base, and neutral solutions.
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Acid: pH<7
Neutral: pH=7 Base: pH>7 |
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Calculate the difference in hydrogen ion concentration between given pH values.
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?
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What are buffers and why are they important to living things?
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A solution that can absorb a lot of acid or base without changing it pH. Helps maintain homeostasis.
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