1. Mass Spectrometry----to evaluate the mass of an atom (the most accurate way)
The degree of deflection is related to the mass. The most massive ions are deflected the least and vice versa.
2. Isotopes: atoms that have the same atomic number, but different mass number. (Same number of protons but different number neutrons.)
3. Mass and charge influence the degree of deflection in the magnetic fields Mass+ deflection-(65cu+<63cu+) charge+ deflection+ (63cu2+>63cu+)
4. The MS provides us: number of isotopes, relative isotopic mass (Ir) of each isotope, relative abundance.
5. Ar=Ir (1) x %abundance (1) +Ir (2) x %abundance (2) +and so on/100
The isotopes are found in the ratio 1.339:1.000
%abundance for isotope=1.000/1.339+1.000
6. Mr= the sum of the number of atoms x Ar: relative formula mass(for molecule and non-molecule substances)/relative molecular mass(only for molecular substances)
7. n=N/NA(6.02x1023)=m/M If the question is calculate the % composition of each element in BaCo3, assume we have 1 mole of BaCo3, we have M(Baco3)g=137.3+12.0+3x16.0=197.3g/mol so we have 197.3g Baco3 so 1mol of Ba=……
8. %element=m(element)/m(compound)x100%
9. Empirical formula-----simplest whole number ratio
Metallic elements and ionic substances--- EF=formula
Covalent substances---EF may be the same or simple whole number ratio of the empirical formula.
10. mass(g) m/M moles(mol) divide by smallest simplest mole ratio-----EF
11. If it doesn’t give the exact mass but the percentage, assume you have 100g…..
You May Also Find These Documents Helpful
-
can be written but cannot be written because the atomic number of an element is constant, but the atomic mass of an element depends upon the relative abundance of its isotopes. Hence, it is necessary to mention the atomic mass of an element…
- 5478 Words
- 22 Pages
Powerful Essays -
The purpose of this investigation was to find the average atomic mass for the element Beanium with three isotopes. The average atomic mass is the average mass of the atoms of the element divided by the total number of atoms. An isotope is an atom with the same number of protons, but different number of neutrons; they are different forms of a single element. Since we knew the isotopes had almost the same amount of sub-atomic particles, we made our hypothesis the following: If the sub-atomic particles are almost exact in amount the total mass, average mass, relative abundance, percent abundance, and the relative mass were also going to be almost exact.…
- 447 Words
- 2 Pages
Satisfactory Essays -
Then from this number the amount of water that was in lost was measured at 1.1 g. After this then the number of moles of anhydrous were calculated from the molar mass of anhydrous. Then the moles of water were calculated. Then the stoichiometric coefficients for each component were calculated. The results found that there was two moles of anhydrous and 35 for water. Thus the empirical formula was found to be:…
- 723 Words
- 3 Pages
Good Essays -
2. Atomic mass is a decimal. Why? It is a weighted average of all naturally occurring isotopes.…
- 832 Words
- 3 Pages
Powerful Essays -
A 100.0-g sample of a compound is composed of 16.3 g of carbon, 32.1 g of chlorine, and…
- 3336 Words
- 20 Pages
Satisfactory Essays -
Isotopes of the same element have the same atomic number but differ in their atomic mass.…
- 4298 Words
- 18 Pages
Good Essays -
| |HT - Mass of an element is compared to Carbon12 and therefore the mass of |12C isotope. | |…
- 1897 Words
- 8 Pages
Good Essays -
A) Isotopes of the same element differ only in the number of electrons they contain.…
- 1388 Words
- 6 Pages
Good Essays -
2. Atoms of the same element that have different numbers of neutrons are called _______. isotopes…
- 450 Words
- 2 Pages
Satisfactory Essays -
4. What is the relationship between an atom’s mass number and an element’s atomic mass?…
- 2317 Words
- 11 Pages
Good Essays -
a) An isotope is when two or more of the same element contains equal number of protons but different numbers of neutrons in the nucleus…
- 1087 Words
- 5 Pages
Good Essays -
What is the approximate percent composition by mass of CaBr2 (formula mass = 200)? 1) 20% calcium and 80% bromine 2) 25% calcium and 75% bromine 3) 30% calcium and 70% bromine 4) 35% calcium and 65% bromine What is the empirical formula for C3H6? 1) CH 2) CH2 3) CH3 4) CH6…
- 3757 Words
- 34 Pages
Satisfactory Essays -
Circumstances of discovery- Janssen discovered helium in 1868 when he was looking in a telescope when he found the yellow spectrum lines of helium. It was also rediscovered by Norman Lockyer, Lockyer was the one who made the name helium.…
- 481 Words
- 2 Pages
Good Essays -
Generally only univalent ions are present, so the only variable would be their masses and thus deflection is based on their mass on charge ratio (m/z) ratio.…
- 819 Words
- 4 Pages
Good Essays -
The Greek letter epsilon in these equations is called the molar absorptivity - or sometimes the molar absorption coefficient.…
- 737 Words
- 3 Pages
Good Essays