Chapter 2 Flashcards
Four elements make up how much of the body?
96%
What are the four elements that make up the body?
carbon, oxygen, hydrogen, and nitrogen
Orbital model
current model used that depicts orbitals, probable regions where an electron is most likely to be located
- shading in regions of greatest electron density results in an electron cloud around nucleus
- useful for predicting behavior of atoms
Atomic number
number of protons in nucleus
Mass number
total number of protons and neutrons in nucleus
Isotopes
structural variations of same element due to different number of neutrons but same number of protons
Atomic weight
average of mass numbers of all isotope forms of an atom
homogeneous mixture
particles are evenly distributed throughout
Solvent
substance present in greatest amount
Solute
substance dissolved in solvent
Colloids
also know as emulsions and are heterogeneous mixtures, meaning that particles are not evenly distributed throughout mixture
Suspensions
heterogeneous mixtures that contain large, visible solutes that do settle out
What is the outermost electron shell called?
valence shell
Ionic bonds
involve the transfer of valence shell electrons from one atom to another
Anion
negative charge and atom has gained one or more electron
Cation
positive charge and atom that has lost one or more electrons
Attraction of opposite charges created what kind of bond?
ionic
What are most ionic compounds?
salts
Covalent bonds
formed by sharing of two or more valence shell electrons between two atoms
Two types of covalent bonds
polar and non polar
Nonpolar covalent bonds
equal sharing or electrons between atoms
Polar covalent bonds
unequal sharing of electrons between 2 atoms
Electronegative
atoms with greater electron-attracting ability
Electropositive
with less electron-attracting ability
Hydrogen bonds
attractive force between electropositive hydrogen of one molecule and an electronegative atom of another molecule
not true bond, more of a weak magnetic attraction
Water
most abundant inorganic compound
Water properties
high heat capacity high heat of vaporization polar solvent properties reactivity cushioning salts
Salts
ionic compounds that dissociate into separate ions in water
All ions are called what?
electrolytes
Electrolytes
can conduct electrical currents in solutions
What balance is vital for homeostasis?
ionic balance