Cam came up with the following hypothesis: Increasing the temperature of a 250 mL sample of water will increase the amount of salt that can be dissolved in the water. Cam wanted to design an experiment based on his hypothesis. What would be the independent variable in Cam’s experiment?

Ibelieve the answer is weathering,hope my answer has you : ) 

Ithink about 50 % of an original isotope's number of atoms remain

Hello,#agreed with joseph002.i got my source also from  source: hope this

Reaction involved in present system is :   c12h22o11 + h2o → 2 c6h12o6the reaction system is obeying following rate law:   rate = k[c12h22o11]thus, it is a first order reaction.now, for 1st order reactionrate constant (k) =  given: initial conc. = 3.0 g, final conc. = 2.7 g, t = 2.5 h∴rate constant (k) =  ∴ k = 0.04215 h-1now, for 1st order reaction, half life = 0.693/k = 0.693/0.04215 = 16.4 hthus correct answer is option b