What sphere is most diffrent from earth

Iwill give extra points to who gets this right

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following equation:

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