92.22% of all the isotopes of an element have a mass of 27.87 amu, 4.69% have a mass of 29.06 amu, and 3.09% have a mass of 30.09 amu. What is the average mass of this element?

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

The primary products of complete combustion of fossil fuels are a. carbon dioxide and water b. methane and water c. carbon monoxide and water d. carbon dioxide and carbon monoxide

Which of these is a density dependent factor? a. epidemic b. earthquake c. drought d. hurricane