Biology Chapter 2 Flashcards
Electrons
Negative charge
Atoms
Basic unit of matter
Ion
An atom that has lost or gained electrons
Element
Pure substance that consists of one type of Atom
Atomic number
Number of protons
Isotope
Atoms of an element that have different number of neutrons
Compound
Substance formed by the chemical combination of two or more elements
Chemical bonds involve
Electrons
Ionic bonds
When one or more electrons are transferred from one atom to another
Covalent bonds
When electrons are shared by Atoms instead of transferred
Molecule
Atoms joined by covalent bonds
Van der wall forces
Slight attraction develops between oppositely charged regions of nearby molecules
Polar
One end of the molecule hydrogen has a slightly positive charge
One end of the molecule oxygen has a slightly negative charge
Hydrogen bonding or H bonds
Due to their polarity water molecules attract each other
Cohesion
Attraction between molecules of the same substance
Adhesion
Attraction between molecules of different substances
Heat capacity
High heat capacity can absorb lots of heat with very little change in temperature
Mixture
Material composed of two or more elements physically combined not chemically
Solutions
Components are evenly distributed
Solute
Substance that is dissolved (like salt)
Solvent
Substance in which solute is dissolved (water)
Suspension
Mixture of a substance and water that does not dissolve or settle out
PH scale
Indicates the concentration of hydrogen ions in solution
Acid
Compound that forms hydrogen ions in solution