Chapter 2 - Atoms and Molecules Flashcards
Unable to divide and still be the same thing.
Element
Number of protons.
Atomic Number
Number of protons, neutrons, and electrons.
Mass
92% of average organisms consist of…
Oxygen, Carbon, Hydrogen, Calcium, Nitrogen, and Phosphorus.
Two or more same atoms held together with chemical bonds. (Ex = O2)
Molecule
Different atoms held together with chemical bonds. (Ex = C6H12O6)
Compound
Strongest, most common, electrically neutral bond… shares electrons. (Ex = Oxygen to Hydrogen in H2O)
Covalent Bonds
Loss or gain of electron from ions to form a stable compound. (Ex = NaCl)
Ionic Bonds
Weak, slightly polar bond, therefore attractive to other slightly polar molecules. (Ex = H2O molecules sticking to other H2O molecules)
Hydrogen Bonds
Water molecules stick together because of the hydrogen bonds.
Cohesion
Resistance to being broken.
Surface Tension
Sticky to slightly charged surfaces. (Ex = Allows plants/trees to deliver water hundreds of feet against gravity)
Adhesion
Universal solvent for life.
Water
“Water-fearing” parts of the membrane.
Hydrophobic
“Water-loving” parts of the membrane.
Hydrophilic
