Moles = mass/molar mass
moles = 2.3
molar mass = 278
=> mass = moles*molar mass = 639.4g
C becuase that is the one that you would have to do becuase that is the only option
I think it’s A but I’m not sure.
It defines the element. If you change the protons, you change the type of element. A proton is positively charged and is most of the mass of the atom, next to the neutron. Neutrons have a very very very slightly higher mass.
Answer is "0.05 mol".
<em>Explanation;</em>
We can do calculation by using a simple formula as
n = m/M
Where, n is the number of moles of the substance (mol), m is the mass of the substance (g) and M is the molar mass of the substance (g/mol).
Here,
n = ?
m = 2.80 g
M = 56.08 g/mol
By substitution,
n = 2.80 g /56.08 g/mol
n = 0.0499 mol ≈ 0.05 mol