If a chemical change requires energy, which of the following could be the source of the energy?
a. heating with a flame
b. settling the mixture for 20 minutes
c. measuring mass from a balance beam
d. adding more substance to the observed material

Acompound has a molecular weight of 12.124 atomic mass units and the empirical formula c3h40. what is the molecular formula of the compound?

Draw the lewis dot structure for each of the following polyatomic ions

Pinene is an unsaturated hydrocarbon found in pine resin. if pinene has m+ = 136 and contains 1 double bond(s) and 2 ring(s); what is its molecular formula? enter the formula in the form ch first, then all other atoms in alphabetical order; do not use subscripts. the formula is case-sensitive