A ___ is scientific knowledge established through direct observation and remains constant. Scientific knowledge can change when scientists ___ for the first one:

A. fact

B. hypothesis

C. theory

for the second one:

A. conduct experiments

B. generate hypothesis

C. hold different opinions

What is the percentage of hydrogen in nitrogen trihydride

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

In the reaction h2co3 (aq) + 3nh3 (aq) = 2 nh4+ (aq) + co3 2-, how many electrons are transferred?