M = Sr (strontium)
<em>Step 1.</em> Calculate the <em>moles of CO_2</em>.
Moles of CO_2 = 0.395 g CO_2 × (1 mol CO_2/44.01 g CO_2)
= 0.008 975 mol CO_2
<em>Step 2</em>. Calculate the <em>moles of MCO_3</em>.
Moles of MCO_3 = 0.008 975 mol CO_2 × (1 mol MCO_3/1 mol CO_2)
= 0.008 975 mol MCO_3
<em>Step 3</em>. Calculate the molar mass of <em>MCO_3</em>
MM = grams/moles = 1.324 g/0.008 75 mol = 147.5 g/mol
<em>Step 4</em>. Calculate the <em>atomic mass of M</em>
M_r = <em>x</em> + 12.01 + 3×16.00 = <em>x</em> + 60.01 = 147.5
<em>x</em> = 147.5 – 60.01 = 87.5
<em>Step 5. Identify M</em>.
The element with the closest atomic mass is Sr (A_r = 87.6).
∴ M = Sr and the compound is SrCO_3.
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.
Answer:
H2O
Explanation:
hydrogen has 1 electron
and oxygen has 6 electron which form a water molecule Atom
Answer:
Gases have no definite shape or volume. They are fluid, allowing particles/molecules to move freely.
The behavior of a gas is that the volume changes directly with temperature. With a constant volume, the pressure will be directly proportional to the amount of gas.
Explanation:
These are some of the properties I can think of
This answer is 24 because 2.17 x 10 -8 is 24 so that would be your answer