The mass of atoms. Objectives Today we will learn: What atomic number and mass number mean The...
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![Page 1: The mass of atoms. Objectives Today we will learn: What atomic number and mass number mean The relative masses of subatomic particles What isotopes are.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e575503460f94b501c6/html5/thumbnails/1.jpg)
The mass of atoms
![Page 2: The mass of atoms. Objectives Today we will learn: What atomic number and mass number mean The relative masses of subatomic particles What isotopes are.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e575503460f94b501c6/html5/thumbnails/2.jpg)
Objectives
• Today we will learn:• What atomic number and mass number mean• The relative masses of subatomic particles• What isotopes are
• That masses of atoms can be compared by their relative atomic masses• That carbon 12 is used as a standard to measure relative atomic mass from• That the relative masses of compounds can be calculated
![Page 3: The mass of atoms. Objectives Today we will learn: What atomic number and mass number mean The relative masses of subatomic particles What isotopes are.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e575503460f94b501c6/html5/thumbnails/3.jpg)
True or False
• Atoms are charged particles• Atoms contain charged particles• Electrons are found in energy levels or shells• Electrons have a negative charge• Protons are found in the nucleus of an atom• Neutrons are found in shells around the outside of an atom
![Page 4: The mass of atoms. Objectives Today we will learn: What atomic number and mass number mean The relative masses of subatomic particles What isotopes are.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e575503460f94b501c6/html5/thumbnails/4.jpg)
What do you know about the atom…
![Page 5: The mass of atoms. Objectives Today we will learn: What atomic number and mass number mean The relative masses of subatomic particles What isotopes are.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e575503460f94b501c6/html5/thumbnails/5.jpg)
Find the number of Protons, Electrons and Neutrons and the mass number of the following…
• Li• Na• Al• C• Ar• Ca• Au
• N• W• Bi• Hg4+
• F-
• Tc3+
![Page 6: The mass of atoms. Objectives Today we will learn: What atomic number and mass number mean The relative masses of subatomic particles What isotopes are.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e575503460f94b501c6/html5/thumbnails/6.jpg)
What about chlorine?
![Page 7: The mass of atoms. Objectives Today we will learn: What atomic number and mass number mean The relative masses of subatomic particles What isotopes are.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e575503460f94b501c6/html5/thumbnails/7.jpg)
Isotope
• Same number of protons different number of neutrons
![Page 8: The mass of atoms. Objectives Today we will learn: What atomic number and mass number mean The relative masses of subatomic particles What isotopes are.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e575503460f94b501c6/html5/thumbnails/8.jpg)
Find the link between these
• 12g of C
• 197g of Au
• 7g of Li• 88g of Sr
• 56g of Fe
• 119g of Sn
• 48g of Ti
• 23g of Na
• 24g of Mg• 91g of Zr• 40g of Ca
• 84g of Kr• 11g of B
• 127g of I
• 80g of Br
• 1g of H
• 75g of As
![Page 9: The mass of atoms. Objectives Today we will learn: What atomic number and mass number mean The relative masses of subatomic particles What isotopes are.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e575503460f94b501c6/html5/thumbnails/9.jpg)
The Mole
• Is based on Avogardos number• 6.022 x 1023 particles in one
mole
![Page 10: The mass of atoms. Objectives Today we will learn: What atomic number and mass number mean The relative masses of subatomic particles What isotopes are.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e575503460f94b501c6/html5/thumbnails/10.jpg)
Find the relative mass of the following…• Li• Na• CO2
• Al2O3
• CH4
• Ar• CaCO3
• Au
• N2
• W• Bi• H2O• CuSO4•5H2O
![Page 11: The mass of atoms. Objectives Today we will learn: What atomic number and mass number mean The relative masses of subatomic particles What isotopes are.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e575503460f94b501c6/html5/thumbnails/11.jpg)
Working out the number of moles
• 12g carbon• 16g oxygen gas• 9g gold• 45g hydrogen• 10g argon
Mass
No Moles Relative Mass
![Page 12: The mass of atoms. Objectives Today we will learn: What atomic number and mass number mean The relative masses of subatomic particles What isotopes are.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e575503460f94b501c6/html5/thumbnails/12.jpg)
Objectives
• Today we will learn:• What atomic number and mass number mean• The relative masses of subatomic particles• What isotopes are• That masses of atoms can be compared by their relative atomic masses• That carbon 12 is used as a standard to measure relative atomic mass from• That the relative masses of compounds can be calculated
• You can now• Define atomic number and mass number• Use the periodic table to get atomic & mass number to work out the number of each subatomic particle
that an atom has• Give a definition of atomic mass• Calculate relative formula masses• State what a mole is
![Page 13: The mass of atoms. Objectives Today we will learn: What atomic number and mass number mean The relative masses of subatomic particles What isotopes are.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e575503460f94b501c6/html5/thumbnails/13.jpg)
Calculations with Percentages, Formulae & Equations• You will learn…
• How to calculate the percentage of an element in a compound from its formula
• How to calculate the empirical formulae of a compound from its percentage composition
• That balanced symbol equations show the relative numbers of molecules of reactants and products in a reaction
• That balanced symbols equations can be used to calculate the masses of reactants and products
• Teaser…• How could you work out the %
of carbon in
CaCO3
![Page 15: The mass of atoms. Objectives Today we will learn: What atomic number and mass number mean The relative masses of subatomic particles What isotopes are.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e575503460f94b501c6/html5/thumbnails/15.jpg)
Percentage of an element in a compound• By Mass!• Find the relative mass of the
compound• Divide the total relative mass of
the element of interest by the relative mass of the compound.
Mass of element of interest
Total Relative mass of substance
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Percentage of an element in a compound• For example…• Find the percentage of oxygen in
magnesium oxide• Magnesium oxide = MgO• Mg = 24• O = 16• MgO = 40• 16/40 = 40%
Mass of element of interest
Total Relative mass of substance
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Questions
![Page 18: The mass of atoms. Objectives Today we will learn: What atomic number and mass number mean The relative masses of subatomic particles What isotopes are.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e575503460f94b501c6/html5/thumbnails/18.jpg)
Empirical Formulae
• Empirical formula HaikuConvert mass to moleThen divide it by the smallMultiply til whole
![Page 19: The mass of atoms. Objectives Today we will learn: What atomic number and mass number mean The relative masses of subatomic particles What isotopes are.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e575503460f94b501c6/html5/thumbnails/19.jpg)
Example
Na S O
Percentage 29.1% 40.5% 30.4%
Convert Mass to
Mole
29.1 / 23 =
1.265217
40.5 / 32
1.265625
30.4 / 16
1.9
Then divide it by the
small
1.2652171.265217
=1
1.2656251.265217
=1
1.91.265217
=1.5
Multiply til whole
X 22 2 3
Convert mass to moleThen divide it by the smallMultiply til whole
![Page 20: The mass of atoms. Objectives Today we will learn: What atomic number and mass number mean The relative masses of subatomic particles What isotopes are.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e575503460f94b501c6/html5/thumbnails/20.jpg)
Questions
![Page 21: The mass of atoms. Objectives Today we will learn: What atomic number and mass number mean The relative masses of subatomic particles What isotopes are.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e575503460f94b501c6/html5/thumbnails/21.jpg)
Calculations with Percentages, Formulae & Equations• You will learn…
• How to calculate the percentage of an element in a compound from its formula
• How to calculate the empirical formulae of a compound from its percentage composition
• That balanced symbol equations show the relative numbers of molecules of reactants and products in a reaction
• That balanced symbols equations can be used to calculate the masses of reactants and products
• You have learnt…• To calculate the percentage
composition of an element in a compound
• To calculate the empirical formulae of compounds from percentage composition.
![Page 22: The mass of atoms. Objectives Today we will learn: What atomic number and mass number mean The relative masses of subatomic particles What isotopes are.](https://reader036.fdocuments.us/reader036/viewer/2022062801/56649e575503460f94b501c6/html5/thumbnails/22.jpg)