A scientist kept 1,000 gram samples of radioactive carbon, radium, and plutonium in three different containers. The table below shows the half-lives of the three radioactive materials.
Radioactive Material
Half-life (in years)
carbon
5,700
radium
1,620
plutonium
6,563
Based on the table, which of these conclusions is most likely correct? (1 point)
After 6,000 years, approximately 250 grams of carbon and radium will be left in the containers.
O After 20,000 years, approximately 500 grams of carbon and plutonium will be left in the containers.
After 6,000 years, approximately 500 grams of carbon and plutonium will be left in the containers.
After 20,000 years, approximately 250 grams of carbon and radium will be left in the containers,

african americans demonstrated their newly found freedom by relocating often in search of relatives whom they had been separated from during slavery. others established schools to educate freed people and they built institutions such as churches and political organizations to advocate for their rights.

- "the choice that is not an indicator of a chemical change is "state of matter changes". more common than not, chemical reactions produce energy in the form of light or heat. along with energy, they also produce a new substance called the product that could be in any state of matter (solid, gas, or liquid)."

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%