GCSE Atomic Structure Flashcards
History of structure of the atom:
Early 1800’s;
In his theory what did dalton state
- All elements are made up of small invisible particles called atoms
- Atoms can’t be created or destroyed
- Atoms of different elements have different properties
- When atoms combine they form molecules or compounds
History of structure of the atom:
1897 ‘Plum Pudding’ model of J.J Thomson: Who discovered the electron
J.J Thomson
History of structure of the atom:
1897 ‘Plum Pudding’ model of J.J Thomson: When J.J Thomson discovered the electron what happened to dalton’s atomic theory
It was modified
History of structure of the atom:
1897 ‘Plum Pudding’ model of J.J Thomson:
What did J.J Thomson propose
He proposed the ‘plum pudding’ model which stated that the negative electrons were embedded in a positive sphere (like the raisins in a plum pudding)
History of structure of the atom:
What happened in 1911
Ernest Rutherford revised J.J Thomson’s model to the model which has electrons orbiting a positive nucleus
History of structure of the atom:
What happened in 1932
James Chadwick discovered the neutron
Comprehension questions:
Who proposed the idea that matter is composed of small indivisible particles called atoms
Democritus and Leucippus
Comprehension questions:
What ideas did Aristotle propose
That matter was composed of 4 ‘elements’, air, earth, fire and water and he used these ideas to explain matter and its behaviour
Comprehension questions:
In 1908 John Dalton published his atomic theory, what did he state
That all elements are made up of small indivisible particles called atoms
Comprehension questions:
Name the scientist who discovered the electron
J.J Thomson
Comprehension questions:
What experiment was Thomson carrying out when he discovered the electron
The way gases conduct electricity
Comprehension questions:
In Thomson’s experiment how did he show the electrons had a negative charge
He passed high voltage across the terminals of a tube containing air and found out that the rays produced travelled in straight lines from the negative terminal and at these rays were deflected when they passed through charged plates
Comprehension questions:
What did Thomson’s model of the atom look like
A plum pudding
Comprehension questions:
How was it similar to a Christmas pudding
There are rings of negative electrons embedded in a sphere of positive charge, just like the currants embedded in a Christmas pudding
Comprehension questions:
Why did Thomson suggest that the atom was neutral
Because it contained equal numbers of positive and negative charges
Comprehension questions:
What did Rutherford discover about the atom
It consisted of electrons revolving around a positively charged nucleus
Comprehension questions:
Where is virtually all of an atoms mass contained
In the nucleus
Comprehension questions:
In what way was Rutherford’s model of the atom similar to planets revolving around the sun
The electrons revolving around the positively charged nucleus were like the planets revolving around the sun
Comprehension questions:
What part of the atom did James Chadwick discover in 1932
He showed that the nucleus of an atom contained 2 different types of particles, protons and new particles called neutrons
Comprehension questions:
How does the mass of a neutron compare with the mass of a proton
It is equal
Fill in the blanks:
Atom is composed of a small, dense, ………… charged nucleus composed of……….and……….with…………charged electrons in…….orbiting the……..
Positively Neutrons Protons Negatively Shells Nucleus
Give the relative mass (atomic mass units), relative charge and position of the following particles:
Proton
Neutron
Electron
Proton:
Relative mass = 1
Relative charge = +1
Position = nucleus
Neutron:
Relative mass = 1
Relative charge = 0
Position = nucleus
Electron:
Relative mass = 1/1840
Relative charge = -1
Position = shells
Definition of atomic number
This is the number of protons in an atom
Definition of mass number
This is the total number of protons and neutrons in an atom
How do the atoms of one element differ from those of another
They always have different numbers of protons as this defines the element, however the number of neutrons and electrons vary to
In the periodic table there are two numbers beside each atomic symbol, what are they called
One is called the mass number and the other is called the atomic number
Fill in the blanks:
The number of protons in an atom is equal to its………..
As an atom is electrically neutral (i.e. No overall charge) then the number of……..must equal the number of………
The number of………in an atom is equal to its……………….. - …………….
Atomic number Electrons Protons Neutrons Mass number Atomic number
Calculate the number of sub atomic particles in each of the following:
Lithium (mass number of 7, atomic number of 3)
P = 3 E = 3 N = 4
Calculate the number of sub atomic particles in each of the following:
Magnesium (with a mass number of 24 and an atomic number of 12)
P = 12 E = 12 N = 12
Calculate the number of sub atomic particles in each of the following:
Oxygen (with a mass number of 16 and an atomic number of 8)
P = 8 E = 8 N = 8
Calculate the number of sub atomic particles in each of the following:
Chlorine(with a mass number of 35 and an atomic number of 17)
P = 17 E = 17 N = 18
Calculate the number of sub atomic particles in each of the following:
Nitrogen (with a mass number of 14 and an atomic number of 7)
P = 7 E = 7 N = 7
Calculate the number of sub atomic particles in each of the following:
Helium (with a mass number of 4 and an atomic number of 2)
P = 2 E = 2 N = 2
Calculate the number of sub atomic particles in each of the following:
Potassium (with a mass number of 39 and an atomic number of 19)
P = 19 E = 19 N = 20
Calculate the number of sub atomic particles in each of the following:
Fluorine (with a mass number of 19 and an atomic number of 9)
P = 9 E = 9 N = 10
Calculate the number of sub atomic particles in each of the following:
Aluminium (with a mass number of 27 and an atomic number of 13)
P = 13 E = 13 N = 14
Calculate the number of sub atomic particles in each of the following:
Boron (with a mass number of 11 and an atomic number of 5)
P = 5 E = 5 N = 6
Calculate the number of sub atomic particles in each of the following:
Beryllium (with a mass number of 9 and an atomic number of 4)
P = 4 E = 4 N = 5
Calculate the number of sub atomic particles in each of the following:
Neon (with a mass number of 20 and an atomic number of 10)
P = 10 E = 10 N = 10
Electronic structure:
Where are electrons arranged and where
In shells around the nucleus
Electronic structure:
What shell do electrons enter first
The shell closest to the nucleus
Electronic structure:
What must happen to each shell before starting to fill the next
Each shell must be filled with its full quota before starting to fill the next shell
Electronic structure:
Shell number 1 (closest to the nucleus) can take how many electrons
A maximum of 2
Electronic structure:
All the other shells bar the first have a maximum of how many electrons
8
Electronic structure:
What is the rule for positioning electrons
In second and subsequent shells, the electrons are placed at 12 o’clock, 3 o’clock, 6 o’clock and 9 o’clock, before being paired in the same order
What is the electronic configuration for lithium (atomic number 3)
2,1
What is the electronic configuration for magnesium (atomic number 12)
2,8,2
What is the electronic configuration for oxygen (atomic number 8)
2,6
What is the electronic configuration for chlorine (atomic number 17)
2,8,7
What is the electronic configuration for nitrogen (atomic number 7)
2,5
What is the electronic configuration for helium (atomic number 2)
2
What is the electronic configuration for potassium (atomic number 19)
2,8,8,1
What is the electronic configuration for fluorine (atomic number 9)
2,7
What is the electronic configuration for aluminium (atomic number 13)
2,8,3
What is the electronic configuration for boron (atomic number 5)
2,3
What is the electronic configuration for beryllium (atomic number 4)
2,2
What is the electronic configuration for neon (atomic number 10)
2,8
How many electrons do each of the following elements have and what is there electronic configuration:
Element A - mass number 9 and has 5 neutrons
Element D - mass number 12 and has 6 neutrons
Element E - mass number 40 and has 22 neutrons
Element G - mass number 39 and has 20 neutrons
Element H - mass number 31 and has 15 neutrons
Element A - has 4 electrons and an electronic configuration of 2,2
Element D - has 6 electrons and an electronic configuration of 2,4
Element E - has 18 electrons and an electronic configuration of 2,8,8
Element G - has 19 electrons and an electronic configuration of 2,8,8,1
Element H - has 16 electrons and an electronic configuration of 2,8,6
If I have an electronic configuration of 2,8,3 and my mass number is 27 what element am I and what is my atomic number
Aluminium and 13
If my mass number is 24 and my atomic number is 12 what element am I and what is my electronic configuration
Magnesium and 2,8,2
If I’m the element fluorine my atomic number is 9, what’s my electronic configuration and mass number
19 and 2,7
If I have an electronic configuration of 2,6 and my mass number is 16 what element am I and what is my atomic number
Oxygen and 8
What’s the definition of an isotope
Isotopes are atoms of an element with the same atomic number but a different mass number indicating a different number of neutrons
What are two common isotopes
Chlorine 35 and chlorine 37
Chlorine 35 has 17 protons, 17 electrons and 18 neutrons
Chlorine 37 has 17 protons, 17 electrons and 20 neutrons
Calculating the relative atomic mass of chlorine from the mass numbers and abundances of isotopes:
Naturally occurring sample,
75% of the atoms will have a mass number of 35
25% of the atoms will have a mass number of 37
Work out the average mass number
Average mass number = (75x35) + (25x37) -------------------- 100 = 35.5
Mass spectrum of isotopes:
Imagine a mass spectrum for an example of chlorine, what is the label on the y axis
Relative abundance
Mass spectrum of isotopes:
Imagine a mass spectrum for an example of chlorine, what does the peak height show you
The relative abundance of each isotope of chlorine
Mass spectrum of isotopes:
Imagine a mass spectrum for an example of chlorine, when the charged is +1 the axis always indicates the mass of the substance. What are the two mass number for the two isotopes of chlorine
35 and 37
Mass spectrum of isotopes:
Imagine a mass spectrum for an example of chlorine, the ration for the peak heights for the sample of chlorine is 3:1 for chlorine 35 and chlorine 37 respectively. Calculate the average RAM for chlorine
4 = 35.5
Use the info below to identify which two are isotopes:
Substance A has 8 protons, 8 neutrons and 8 electrons
Substance B has 10 protons, 10 neutrons and 10 electrons
Substance C has 8 protons, 10 neutrons and 8 electrons
Substance D has 8 protons, 8 neutrons and 10 electrons
A and C
Complete the following to show the number of protons men neutrons and electrons in the three isotopes of carbon:
An isotope of carbon has a mass number of 12 and an atomic number of 6
An isotope of carbon has a mass number of 13 and an atomic number of 6
An isotope of carbon has a mass number of 14 and an atomic number of 6
Isotope 1: 6 electrons, 6 protons and 6 neutrons
Isotope 2: 6 electrons, 6 protons and 7 neutrons
Isotopes 3: 6 electrons, 6 protons and 8 neutrons
Chlorine exists naturally as 2 isotopes chlorine 35 and chlorine 37 in the ratio 3:1 respectively.
Show why the relative atomic mass of chlorine is 35.5
4 = 35.5
Calculate the relative atomic mass of boron given that it contains 20% boron 10 and 80% boron 11
RAM = (20x10) + (80x11) ------------------ 100 = 10.8
Which one of the following is not found in the nucleus of an atom;
Proton, neutron, electron
Electron
Uranium has two common isotopes, uranium 235 and uranium 238, (both have an atomic number of 92)
What is the atomic number of uranium
92
Uranium has two common isotopes, uranium 235 and uranium 238, (both have an atomic number of 92)
Why does uranium 238 have a greater atomic number than the uranium 235 isotope
Because it has 3 extra neutrons
Uranium has two common isotopes, uranium 235 and uranium 238, (both have an atomic number of 92)
Give one way in which atoms of the two uranium isotopes are similar
They have the same number of protons and electrons (same atomic number)
Chlorine exists as 2 isotopes, chlorine 35 and chlorine 37:
Give one way in which these isotopes are similar
They are the same element due to the atomic number
Chlorine exists as 2 isotopes, chlorine 35 and chlorine 37:
Give one way in which these two isotopes are different
They have different mass numbers
A sample of silicon contains 92.18% silicon 28, 4.70% silicon 29 and 3.12% silicon 30. Calculate the RAM of silicon
RAM = (92.18x28) + (4.70x29) + (3.12x30) ------------------------------------- 100 = 28.11
Atoms into ions:
Atoms with electric charges are called….
Ions
Atoms into ions:
Those with positive charges are called……
Cations
Atoms into ions:
Those with negative charges are called……
Anions
Formation of cations (positive ions): Sodium atom -----> sodium ion P = 11 E = 11 2,8,1 -------> N = 12
Loses Na+
——-> P = 11 2,8
1 electron E = 10
N = 12
Formation of cations (positive ions): Calcium atom -----> calcium ion P = 20 E = 20 2,8,8,2 -------> N = 20
Loses Ca2+
——-> P = 20 2,8,8
2 electrons E = 18
N = 20
Formation of cations (positive ions): Aluminium atom -----> aluminium ion P = 13 E = 13 2,8,3 -------> N = 14
Loses Al3+
——-> P = 13 2,8
3 electrons E = 10
N = 14
Formation of anions (negative ions): Chlorine atoms -----> chloride ion P = 17 E = 17 2,8,7 -------> N = 18
Gains Cl-
——-> P = 17 2,8,8
1 electron E = 18
N = 18
Formation of anions (negative ions): Oxygen atom -----> oxygen ion P = 8 E = 8 2,6 -------> N = 8
Gains O2-
——-> P = 8 2,8
2 electrons E = 10
N = 8
Formation of anions (negative ions): Nitrogen atom -----> nitrogen ion P = 7 E = 7 2,5 -------> N = 7
Gains N3-
——-> P = 7 2,8
3 electrons E = 10
N = 7
GENERAL RULE
Metals form positive ions
Non metals form negative ions
What do u find in every science lab
A periodic table
How is the periodic table arranged
By atomic number
The atomic number tells us the number of protons in an element, what else does it tell us
The number of electrons orbiting the nucleu