The answer should by C i believe, if not let me know, and i will correct myself
Answer:
34.15% is the mass percentage of calcium in the limestone.
Explanation:
Mass of precipitate that is calcium oxalate = 140.2 mg = 0.1402 g
1 mg = 0.001 g
Moles of calcium oxalate = 
1 mole of calcium oxalate have 1 mole of calcium atom.
Then 0.001095 moles of calcium oxalate will have 0.001095 moles of calcium atom.
Mass of 0.001095 moles of calcium :
0.001095 mol × 40 g/mol = 0.04381 g
Mass of sample of limestone = 128.3 mg = 0.1283 g
Percentage of calcium in limestone:

34.15% is the mass percentage of calcium in the limestone.
T <span>The process in nature that breaks down rocks is called physical weathering.</span>
Answer:
1. went on the first manned launch during the Apollo mission
2. responsible for all spacecraft systems
3. 4500 hour
4. published All-American Boys
5. Joined back in space organization as a consultant to inspire next generation for mars
K2O + CaBr2 ---> CaO + 2 KBr
Unable to read second question properly sorry