O=C=O, it’s a double bond between the carbons and oxygen
It's Bromine(Br-) Group 17 element that has 7 valence electrons on the fourth energy level.
Answer:
0.305 mol
Explanation:
Ca(NO) is not a molecule. I think you meant to type Ca(NO3)2, which is calcium nitrate.
The moles of a compound is equal to is mass divided by its molar mass.
The molar mass of Ca(NO3)2 is 164.09 g/mol.
50.0 / 164.09 = 0.305
All the elements you listed share a common trait: they are synthetic, radioactive elements. These elements do not have a stable isotope, so for a radioactive element, its most stable isotope's atomic mass will be listed in parentheses.
One such example would be plutonium. This element has 6 different isotopes with differing half-lives. The most stable isotope for plutonium is plutonium-244, with a half-life of around 80 million years. Therefore, the atomic mass listed for plutonium will be (244).