You are asked to prepare 500. mL of 0.400 M Ba(NO3)2 solution? You have solid barium nitrate, distilled water, a balance and a choice of volumetric flasks (1.00 L, 0.500 L, and 0.250 L) Describe how you would prepare this solution. Show your calculations and list the steps in the correct order.

Asample of radium-226 will decay 1/4 of its original amount after 3200years. what is the half-life of radium-226?

What happens to isotopes that are unstable?

Consider the reduction reactions and their equilibrium constants. cu+(aq)+e−↽−−⇀cu(s)pb2+(aq)+2e−↽−−⇀pb(s)fe3+(aq)+3e−↽−−⇀fe(=6.2×108=4.0×10−5=9.3×10−3 cu + ( aq ) + e − ↽ − − ⇀ cu ( s ) k =6.2× 10 8 pb 2 + ( aq ) +2 e − ↽ − − ⇀ pb ( s ) k =4.0× 10 − 5 fe 3 + ( aq ) +3 e − ↽ − − ⇀ fe ( s ) k =9.3× 10 − 3 arrange these ions from strongest to weakest oxidizing agent.