What element corresponds to period 5, group 2

An aqueous solution of calcium hydroxide is standardized by titration with a 0.120 m solution of hydrobromic acid. if 16.5 ml of base are required to neutralize 27.5 ml of the acid, what is the molarity of the calcium hydroxide solution?

Upon decomposition, one sample of magnesium fluoride produced 1.65 kg of magnesium and 2.56 kg of fluorine. a second sample produced 1.32 kg of magnesium. part a how much fluorine (in grams) did the second sample produce?

Select all the correct answers. which compounds have the empirical formula ch20? (multiple answers)a. c2h4o2b. c3h603c. ch2o2d. c5h1005e. c6h1206