Modern masonry fireplaces are based on designs first developed
a) during the little ice age
b) in the late 1800's
c) after wwii
d) in this decade

Pauling and lewis questioned the extreme definitions of bonds. they wondered if bonds might be described somewhere in between the two extremes (covalent and ionic). on the basis of experimental data,pauling confirmed that bonds could be ionic, covalent, and for those, in between, exhibit a degree of ionic character. he theorized that the major factor was how strongly the atoms in the bond attracted the electrons. pauling called this factor - the tendency of an atom to attract electrons in a bond.

The atomic radius of sodium is 186 pm and of chlorine is 100 pm. the ionic radius for na+ is 102 pm and for cl– is 181 pm. in going from na to cl in period 3, why does the atomic radius decrease while the ionic radius increases? a. the inner electrons in the sodium cation shield its valence electrons more effectively than the inner electrons in the chloride anion do. b. the inner electrons shield the valence electrons more effectively in the chlorine atom than in the chloride anion. c. the outermost electrons in chloride experience a smaller effective nuclear charge than those in the sodium cation do. d. the outermost electrons in chloride experience a larger effective nuclear charge than those in the sodium cation do. e. monatomic ions are bigger than the atoms from which they are formed.

Aglow stick contains a glass vial with chemicals. when the glow stick is bent, the vial breaks and the chemicals react to produce a glow. a science student observes that a glow stick kept in the freezer glows for a longer duration than a glow stick kept at room temperature. what conclusion can be drawn based on the observation? be sure to note the outcome and test variables in the conclusion.