Answer:
it is Calcium (Ca)
4th period, 2nd group, 2 valence electrons
<u>Answer:</u> The mass of iron in the ore is 10.9 g
<u>Explanation:</u>
We are given:
Mass of iron (III) oxide = 15.6 g
We know that:
Molar mass of Iron (III) oxide = 159.69 g/mol
Molar mass of iron atom = 55.85 g/mol
As, all the iron in the ore is converted to iron (III) oxide. So, the mass of iron in iron (III) oxide will be equal to the mass of iron present in the ore.
To calculate the mass of iron in given mass of iron (III) oxide, we apply unitary method:
In 159.69 g of iron (III) oxide, mass of iron present is 
So, in 15.6 g of iron (III) oxide, mass of iron present will be = 
Hence, the mass of iron in the ore is 10.9 g
Simple!
Atomic number= number of protons AND number of electrons (in an atom)
Mass number= number of neutrons
One of the many ways in order to solve for the vapor pressure of pure components at a given temperature is through the Antoine's equation which is written below,
P = 10^(A - B/C+T)
where A, B, and C are constants and T is the temperature in °C and P is the vapor pressure in mm Hg.
For hexane,
A = 7.01
B = 1246.33
C = 232.988
Substituting the known values,
P = 10^(7.01 - 1246.33/232.988+25)
<em> P = 151.199 mm Hg</em>
Answer:
No. of electrons of the element