Which radioactive isotope might be most useful to date an artifact that was found in a rock layer just above the Cretaceous-Tertiary impact

When a septic tank backs up a goes in to clean it out

Percent ionization for a weak acid (ha) is determined by the following formula: percent ionization=[ha] ionized[ha] initial×100%for strong acids, ionization is nearly complete (100%) at most concentrations. however, for weak acids, the percent ionization changes significantly with concentration. the more diluted the acid is, the greater percent ionization.a certain weak acid, ha, has a ka value of 9.4×10? 7.part acalculate the percent ionization of ha in a 0.10 m solution.part bcalculate the percent ionization of ha in a 0.010 m solution

Calculate the temperature rise when 0.2g of propane is used to heat 400cm cubed of water.