How many days will it take for 80 grams of Iodine-131 to decay to 5 grams?

What pressure will be exerted by 0.675 moles of a gas at 25*c if it is in a 0.750-l container?

If a solution is considered basic, then a) the hydroxide ion and hydronium ion concentrations are equal. b) the hydroxide ion concentration is less than the hydronium ion concentration. c) the hydronium ion concentration is greater than the hydroxide ion concentration. d) the hydroxide ion concentration is greater than the hydronium ion concentration.

Find the number of grams of hcl needed to react completely with .50 moles of magnesium.