I suppose that you think to the radioactive isotope Cs-17; After 4 years remain 9,122 g.
5g would remain
2 1/2 g
2 1/2 g
As you did not specify an isotope of cesium, I will assume you meant natural cesium. Natural cesium is not radioactive so it does not decay. There will always be the same 10 g of cesium, no matter how long you wait.
The equation for half-life is ... AT = A0 2 (-T/H) ... where A0 is the starting activity, AT is the activity at some time T, and H is the half-life, in units of T. 55134Cs has a half-life of 2.0652 years. Plugging in the known values, we get ... AT = 5.8 2 (-11.5/2.0652) AT = 5.8 2 -5.5685 AT = 0.12222
5g would remain
2 1/2 g
2 1/2 g
2 1/2 g
2 1/2 g
2 1/2 g
1 1/4 g (apex)or 1.25 g
You must know the half life of Caesium to calculate this.
As you did not specify an isotope of cesium, I will assume you meant natural cesium. Natural cesium is not radioactive so it does not decay. There will always be the same 10 g of cesium, no matter how long you wait.
2 1/2g
Since the half-life of cesium-137 is about 30 years, 3 half-lives would have passed in 90 years. The first half-life would leave .5 mg of cesium-137. The second would leave .25 mg, and the third half-life would leave .175 mg of cesium-137.
100g