To count the number of valence electrons we look at the electronic configuration and add the electrons form the electronic shell with the highest principal quantum number.
Rb: [Kr] 5s¹ - 1 valence electron
Xe: [Kr] 5s² 4d¹⁰ 5p⁶ - 8 valence electrons
Sb: [Kr] 5s² 4d¹⁰ 5p³ - 5 valence electrons
I: [Kr] 5s² 4d¹⁰ 5p⁵ - 7 valence electrons
In: [Kr] 5s² 4d¹⁰ 5p¹ - 3 valence electrons
Rank from most to fewest valence electrons:
Xe > I > Sb > In > Rb
Answer:
Option C. 1.60x10^26 molecules
Explanation:
Avogadro's hypothesis proved that that 1 mole of any substance contains 6.02x10^23 molecules.
From the above, we understood that 1 mole of CCl4 contains 6.02x10^23 molecules.
If 1 mole of CCl4 contains 6.02x10^23 molecules,
then, 265 moles of CCl4 will contain = 265 x 6.02x10^23 = 1.60x10^26 molecules
From the calculation made above, 265 moles of CCl4 contains 1.60x10^26 molecules.
Answer:
The value is ![L = 0.985 \pm 0.00801 \ g](https://tex.z-dn.net/?f=L%20%20%3D%20%200.985%20%5Cpm%200.00801%20%5C%20%20g)
Explanation:
From the question we are told that
The molar mass of
is ![MW = 100.085 \ g/mol](https://tex.z-dn.net/?f=MW%20%20%3D%20%20100.085%20%5C%20%20g%2Fmol)
The total mass is
The uncertainty of the total mass is ![\Delta g = 0.1](https://tex.z-dn.net/?f=%5CDelta%20g%20%20%3D%200.1)
Generally the molar weight of calcium is ![M_c = 40 g/mol](https://tex.z-dn.net/?f=M_c%20%20%3D%20%2040%20g%2Fmol)
The percentage of calcium in calcite is mathematically represented as
![C = \frac{40.07}{100.085} * 100](https://tex.z-dn.net/?f=C%20%3D%20%20%5Cfrac%7B40.07%7D%7B100.085%7D%20%2A%20100)
![C = 40.03 \%](https://tex.z-dn.net/?f=C%20%3D%20%2040.03%20%5C%25%20)
Generally the mass of each sample is mathematically represented as
![m= \frac{m_g}{5}](https://tex.z-dn.net/?f=m%3D%20%20%5Cfrac%7Bm_g%7D%7B5%7D)
![m= \frac{12.3}{5}](https://tex.z-dn.net/?f=m%3D%20%20%5Cfrac%7B12.3%7D%7B5%7D)
![m= 2.46 \ g](https://tex.z-dn.net/?f=m%3D%202.46%20%5C%20%20g%20)
Generally mass of calcium present in a single sample is mathematically represented as
![m_c = 2.46 * \frac{40.04}{100}](https://tex.z-dn.net/?f=m_c%20%3D%202.46%20%2A%20%20%5Cfrac%7B40.04%7D%7B100%7D)
![m_c = 0.985 \ g](https://tex.z-dn.net/?f=m_c%20%3D%200.985%20%5C%20%20g%20)
The uncertainty of mass of a single sample is mathematically represented as
![k = \frac{\Delta g }{5}](https://tex.z-dn.net/?f=k%20%20%3D%20%20%5Cfrac%7B%5CDelta%20g%20%7D%7B5%7D)
![k = \frac{0.1 }{5}](https://tex.z-dn.net/?f=k%20%20%3D%20%20%5Cfrac%7B0.1%20%7D%7B5%7D)
![k = 0.02\ g](https://tex.z-dn.net/?f=k%20%20%3D%20%200.02%5C%20%20g%20)
The uncertainty of mass of calcium in a single sample is mathematically represent
![G = 0.00801 \ g](https://tex.z-dn.net/?f=G%20%20%3D%20%200.00801%20%5C%20%20g%20)
Generally the average mass of calcium in each sample is
![L = 0.985 \pm 0.00801](https://tex.z-dn.net/?f=L%20%20%3D%20%200.985%20%5Cpm%200.00801)
First, find out how many grams are in one mole of CO2(the two oxygen atoms means you need to multiply oxygen’s amu by 2,then add whatever carbon’s amu is to that). Then divide 26 grams by that number and that will be your moles. There are only two significant figures, so round your answer correctly.