At the beginning of an experiment, a scientist has 260 grams of radioactive goo. After 210 minutes, her sample has decayed to 8.125 grams. What is the half-life of the goo in minutes? Find a formula for \( G(t) \), the amount of goo remaining at time \( t \). \( G(t)= \)

(iii) Identify the metal which reacts both with acid and alkali to liberate hydrogen: a. Mg b. Zn c. Cu d. Ag

At the beginning of an experiment, a scientist has 172 grams of radioactive goo. After 60 minutes, her sample has decayed to 5.375 grams. What is the half-life of the goo in minutes? Find a formula for \( G(t) \), the amount of goo remaining at time \( t \). \( G(t)= \) How many grams of goo will remain after 20 minutes? You mav enter the exact value or round to 2 decimal places.

Example: 50. OmL of monoprotic acid solution of unknown concentration is titrated with 0.32 M of NaOH. It takes 24.6 mL of this base to reach the endpoint. What is the molarity of this acid?

The half-life of Radium- 226 is 1590 years. If a sample contains 500 mg , how many mg will remain after 4000 years?

(b) Fill in the blanks. (i) Hydrogen is prepared in the laboratory by the reaction of hydrochloric acid. (ii) The number of shells is equal to the number of (iii) Arsine gas is an impurity present in hydrogen which can be removed by passing the gas (iv) Hydrough is not collected by the downward displacement of air, because it forms (v) Group with air.