The half-life of Radium-226 is 1590 years. If a sample contains 300 mg, how many mg will remain after 1000 years

c is the answer because when something is left after something evaporates that shows the chemical change.

plants need sunlight, water, and carbon dioxide to make food. plants use the raw materials of water, nutrients they absorb from soil, and carbon dioxide to make sugars the plant can use. energy from the sun and chlorophyll are also needed.

i'm pretty sure its b i might be wrong though!