It means it is an ion. It has lost two protons making it a positive ion.
Hey there!:
Number of moles = ( number of atoms / 6.023*10²³ atoms )
given number of atoms = 5.03*10²⁴
Therefore:
Number of moles B = 5.03*10²⁴ / 6.023*10²³
Number of moles B = 8.35 moles
Hope that helps!
Answer:
points
Explanation: suggest watching a video
Answer: 40.1%
Explanation: The mass of calcium in this compound is equal to 40.1 grams because there's one atom of calcium present and calcium has an atomic mass of 40.1 . The molar mass of the compound is 100.1 grams. Using the handy equation above, we get: Mass percent = 40.1 g Ca⁄100.1 g CaCO3 × 100% = 40.1% Ca.