Chapter 4: The Periodic Table Flashcards
What four elements did Greek Philosophers believe the universe was made up of?
(4)
- water
- fire
- earth
- air
Who believed the universe was made up of four elements of fire, water, earth and air?
-Greek philosophers
Greek philosophers believed that fire, water, earth and air made up what?
-the universe
What did the theory that the universe was made up of four elements become the basis of?
-chemical theory
What became the basis of chemical theory?
-that the universe was made of four elements
What two scientists made a great contribution to the modern development of our understanding of the idea of an element?
(2)
- Robert Boyle
- Humphry Davy
What did Robert Boyle and Humphry Davy both contribute to?
-the modern development of our understanding of the idea of an element
Who first gave an accurate definition of an element?
-Robert Boyle
Who was Robert Boyle?
-an Irish chemist born in Lismore Castle, Co. Waterford
What did Robert Boyle first give an accurate definition of?
-an element
Who was an Irish chemist born in Lismore Castle, Co. Waterford?
-Robert Boyle
Why is water not an element?
-because it can be split into hydrogen and oxygen
What is formed when elements combine together in chemical reactions?
-a compound
When is a compound formed?
-when elements are combined together
What are combined together to form a compound?
-elements
Some of the most important discoveries in the history of the elements were made by what English chemist?
-Humphry Davy
Who was Humphry Davy?
-an English chemist
What elements did Humphry Davy discover?
6
- potassium
- sodium
- calcium
- barium
- strontium
- magnesium
Potassium, sodium, calcium, barium, strontium and magnesium were discovered by who?
-Humphry Davy
How dud Humphry Davy discover potassium?
-by passing electricity through a compound of potassium
What did Humphry Davy pass through a compound of potassium to discover the element potassium?
-electricity
What did Humphry Davy pass electricity through to discover potassium?
-a compound of potassium
A compound of what was electricity passed through by Humphry Davy to discover potassium?
-a compound of potassium
What four chemists tried to order the elements?
4
-Johann Dobereiner
-John Newlands
Dmitri Mendeleev
-Henry Moseley
Who was Johann Dobereiner?
-a German chemist
Who noticed that the element bromine seemed halfway between those of chlorine and iodine?
-Johann Dobereiner
What did Johann Dobereiner notice?
-he noticed that bromine seemed halfway between those of chlorine and iodine
What did Johann Dobereiner notice about the properties from chlorine to bromine to iodine?
-there was a smooth gradation of properties
What elements did Dobereiner notice a gradation of properties from?
-from chlorine to bromine to iodine
Besides the gradation of properties what did Dobereiner look at in relation to elements?
-the atomic weights of elements
What is the modern name for atomic weight?
-relative atomic mass
What was the relative atomic mass used to be called?
-atomic weight
What did Dobereiner notice about the atomic weight of bromine?
-it was about half way between that of chlorine and iodine
What element did Dobereiner notice the atomic weight was about half way between that of chlorine and iodine?
-bromine
Between iodine and what element did Dobereiner notice the atomic weight of bromine was half way between?
-chlorine
Between chlorine and what element did Dobereiner notice the atomic weight of bromine was half way between?
-iodine
What did Dobereiner call his groups of three elements?
-a triad
Why were Dobereiner’s triads looked on as coincidences that were of little significance?
-few other cases of triads could be found
What resulted when few other cases of Dobereiner’s triads could be found?
-they were looked on as coincidences that were of little significance
Why is Dobereiner’s work important?
-it was the earliest attempt to trace a relationship between properties of the elements and their atomic weights
Who’s work was the earliest attempt to trace a relationship between properties of the elements and their atomic weights?
-Dobereiner
What did Dobereiner attempt to trace a relationship between?
-properties of the elements and their atomic weights
Who was John Newland?
-an English analytical chemist
Who was an English analytical chemist?
-John Newlands
How did Newlands arrange the elements?
-in order of their atomic weights
Who ordered the elements in order of their atomic weights?
-John Newlands
What did Newlands notice when he ordered the elements in increasing atomic weights?
-he noticed that the properties of the elements seemed to repeat with every eight element
Who noticed that the properties of the elements seemed to repeat with every eight element?
-John Newlands
When did Newlands notice the properties of the elements repeated themselves when ordered in increasing atomic weights?
-every eight element
When did John Newland notice that the properties of the element repeated themselves every eight?
-when ordered in increasing atomic weights?
What was missing from Newlands’ table?
-the noble gases
Why were the noble gases missing from Newlands’ table?
-they had not yet been discovered
What did Newland not realise?
-some elements had not yet been discovered
What should Newlands left in his table?
-gaps
What shouldn’t Newlands had done?
-tried to force all the known elements to fit into his table
What did Newlands’ try to do to all the known elements?
-force them into his table
For what elements did Newlands’ Law of Octaves work?
-the first sixteen
What happened after the first sixteen elements in Newlands’ table?
-some of the elements were forced into the wrong groups
What did it mean if Newlands’ Law of Octaves didn’t work?
-there was little or no similarity between a first element and its corresponding eight element
What did it mean if there was little or no similarity between a first element and its corresponding eight element in Newlands’ table?
-it meant his Law of Octaves didn’t work
Why would Newlands’ Law of Octaves not work for the modern Periodic Table?
-the noble gases have been discovered since Newland put forward his law
Who was Dmitri Mendeleev?
-professor of chemistry at the University of St. Petersburg, Russia
Who was a professor of chemistry at the University of St. Petersburg Russia?
-Dmitri Mendeleev
In what way did Dmitri Mendeleev order the elements?
-in order of increasing atomic weight and placed elements with similar properties under each other in groups
Who ordered the elements in increasing atomic weight and placed elements with similar properties under each other in groups?
-Dmitri Mendeleev
What periodic recurrence did Mendeleev notice?
-every eight element had similar properties under each other in groups
How did Mendeleev demonstrate the regular repetition of properties?
-he placed all elements with similar properties in the same vertical column as part of a table
Who placed all elements with similar properties in the same vertical column as part of a table?
-Dmitri Mendeleev
What did Mendeleev demonstrate by placing all elements with similar properties in the same vertical column as part of a table?
-the regular repetition of properties
Why was Mendeleev’s table called the periodic table of elements?
-because the properties of the elements repeated at regular intervals or periodically
What was Mendeleev’s table called because the properties of the elements repeated at regular intervals or periodically?
-the periodic table of elements
What did Mendeleev leave in his table?
-gaps
Who left gaps in his table?
-Mendeleev
Why did Mendeleev leave gaps in his table?
-to make all the known elements fit into the proper group (column)
What did Mendeleev say that the gaps in his table represented?
-they represented elements that had not yet been discovered
What did Mendeleev predict?
-the properties of undiscovered elements
What was eventually found out about Mendeleev’s table?
-the properties predicted by Mendeleev were almost identical to the observed properties
What did Mendeleev do to the order of certain elements?
-reversed them
Why did Mendeleev have to reverse the order of some elements?
-so that each element would be in a group with elements of similar properties
How did Mendeleev make certain elements fall into groups of elements with similar properties?
-by reversing their order
What did Mendeleev realise about the properties of elements?
-the properties were more important than the atomic weights
What two elements did Mendeleev reverse the order of?
2
- iodine
- tellurium
What element was named after Mendeleev?
-mendelevium
Who provided an explanation for why Mendeleev had to revers the order of some elements?
-Henry Moseley
Who was Henry Moseley?
-an English scientist
What did Moseley study?
-the frequencies of the x-rays emitted by atoms of the different elements
What did Moseley study that were emitted by atoms of the different elements?
-x-rays
What x-rays did Moseley study?
-those emitted by atoms of the different elements
What did Moseley discover about the frequencies of the x-rays emitted by atoms of the different elements?
-he found that the frequencies varied with the quantity of positive charge in the nucleus
What did Moseley find varied with the quantity of positive charge in the nucleus?
-the frequencies of the x-rays emitted by atoms of the different elements
What did the frequencies of the x-rays emitted by atoms of the different elements vary with?
-the quantity of positive charge in the nucleus
What did Moseley discover?
-a method of determining the number of protons in the nucleus of an atom
What did Moseley discover a method of doing?
-determining the number of protons in the nucleus of an atom
What did Moseley’s discovery bring about a major improvement in?
-Mendeleev’s table
What did Moseley showed happened when the elements were arranged in order of increasing atomic number?
-that it was not necessary to revers the order of some elements as Mendeleev had to
When did Moseley not have to reverse the order of some elements as Mendeleev had to?
-when the elements were arranged in order of increasing atomic number
What did Moseley’s x-ray studies prove?
-that Mendeleev had been correct in placing tellurium before iodine in spite of the higher atomic weight of tellurium
What did Moseley show happened when the elements were arranged in order of increasing atomic number?
-the elements fall naturally into the correct groups
What did Moseley do to make the elements fall naturally into the correct groups?
-he arranged them in order of increasing atomic order
Who was the man who made the final step from Mendeleev’s Periodic table to the modern Periodic Table?
-Moseley
What did Moseley’s work confirm?
-the position of the elements
How is the way that the elements are arranged differently in the modern periodic table compared to Mendeleev’s?
-in the modern table they are ordered in increasing atomic number while in Mendeleev’s they were arranged in order of increasing atomic weight (relative atomic mass)
What table contains more elements then Mendeleev’s?
-the modern periodic table
What does the modern periodic table have more than of Mendeleev’s?
-elements
Why does the modern periodic table have more elements then Mendeleev’s?
-when Mendeleev constructed his table some elements had not been discovered
About how many elements were in Mendeleev’s table?
-60
Over how many elements are in the modern periodic table?
-100
What is in Mendeleev’s table that are not in the modern periodic table?
-gaps
Why did Mendeleev’s periodic table contain gaps?
-for undiscovered elements
Where are the transition elements listed in the modern periodic table?
-they are listed in a sperate block in the middle of the periodic table
What are listed in a separate block in the middle of the modern periodic table?
-the transition elements
Where did Mendeleev put the transition elements?
-he didn’t put them in a separate block and included them with the other elements
What are the main four features of Mendeleev’s Periodic Table?
(4)
-elements arranged in order of increasing atomic weight (relative atomic mass)
-only 60 elements approx. as not all elements have been discovered
-contains gaps for undiscovered elements
transition elements were not put in a separate block
What are the four main features of the Modern Periodic Table?
(4)
- elements are arranged in order of increasing atomic number
- over 100 elements
- no gaps present
- transition elements are in a separate block
What does the periodic table summarise?
-an enormous amount of information and has brought order into chemistry
What are the three important uses of the Periodic Table?
3
- obtaining atomic numbers and mass numbers
- obtaining relative atomic masses
- writing electron configurations
Why must mass numbers always be whole numbers?
-as it is the number of protons plus neutrons
Who built the mass spectrometer?
-Francis William
What did Francis William Aston build?
-a mass spectrometer
What does a mass spectrometer measure?
-the masses of atoms
What measures the masses of atoms?
-mass spectrometer
Who was Francis William Aston?
-an English chemist
What did Aston find neon gas consisted of?
-two varieties of neon atoms
Who discovered neon gas consisted of two varieties of neon atoms?
-Francis William Aston
What did Aston discover was made of two varieties of neon atoms?
-neon gas
What are the mass numbers of the two varieties of neon atoms found in neon gas?
(2)
- 20
- 22
What did Aston conclude about neon gas?
-it consisted of atoms of neon that differ in the number of neutrons in the nucleus
Who concluded that neon gas consisted of atoms of neon that differ in the number of neutrons in the nucleus?
-Francis William Aston
What type of atoms did Aston conclude neon gas consisted of?
-atoms of neon that differ in the number of neutrons in the nucleus
What did Aston conclude differed about the atoms of neon found in neon gas?
-the number of neutrons
What are the two varieties of neon atoms found in neon gas said to be?
-isotopes of neon
What are said to be isotopes of neon?
-the two varieties of neon atoms found in neon gas
How many neutrons are in the first isotope of neon?
-10 neutrons
What isotope of neon contains 10 neutrons?
-the first isotope
How many neutrons are in the second isotope of neon?
-12 neutrons
What isotope of neon contains 12 neutrons?
-the second isotope
Besides the isotopes of neon what other isotopes did he identify?
-two isotopes of chlorine
How many isotopes does chlorine have?
-two
How many isotopes does carbon have?
-three
How many isotopes does hydrogen have?
-three
What are the two isotopes of chlorine?
2
- chlorine-35
- chlorine-37
What are the three isotopes of carbon?
3
- carbon-12
- carbon-13
- carbon-14
What are the three isotopes of hydrogen?
3
- hydrogen-1
- hydrogen-2
- hydrogen-3
Besides detecting the presence of isotopes what did Aston determine?
-the percentages of each of the isotopes present in a sample of the naturally occurring element
Who determined the percentages of each of the isotopes present in a sample of the naturally occurring element?
-Francis William Aston
What did Aston determine the percentage of?
-each of the isotopes present in a sample of the naturally occurring element
What did Aston determine the percentages of each isotope of present in?
-a sample of the naturally occurring element
Aston determined the percentages of each isotope present in a sample of the naturally occurring what?
-element
What did Aston discover on his study of chlorine gas?
-there were approximately three times as many chlorine-35 atoms as there were chlorine-37 atoms
During his study of chlorine gas what did Aston discover there were three times more of than the chlorine-37 atoms?
-chlorine-35 atoms
What can a mass spectrometer do?
3
- sperate and identify isotopes
- measure the relative abundances of isotopes
- measure the relative atomic mass of an element
What are the five main processes that occur in a mass spectrometer?
(5)
- vaporisation
- ionisation
- acceleration
- separation in a magnetic field
- detection
What is the first process that occurs in a mass spectrometer?
-vaporisation
What is the second process that occurs in a mass spectrometer?
-ionisation
What is the third process that occurs in a mass spectrometer?
-acceleration
What is the fourth process that occurs in a mass spectrometer?
-separation in a magnetic field
What is the fifth process that occurs in a mass spectrometer?
-detection
When does vaporisation take place in a mass spectrometer?
-first
When does ionisation take place in a mass spectrometer?
-second
When does acceleration take place in a mass spectrometer?
-third
When does separation in a magnetic field take place in a mass spectrometer?
-fourth
When does detection take place in a mass spectrometer?
-fifth
During the vaporisation stage of mass spectrometry what is injected into the instrument at the sample inlet?
-a small amount of the gas or liquid
During the vaporisation stage of mass spectrometry where is a small amount of the gas or liquid injected into the instrument?
-at the sample inlet
During the vaporisation stage of mass spectrometry what is done to a small amount of the gas or liquid?
-it is injected into the instrument at the sample inlet
In what stage of mass spectrometry is a small amount of the gas or liquid injected into the instrument at the sample inlet?
-vaporisation
Why do liquids quickly turn to gas in a mass spectrometer?
-as there is a very good vacuum inside the instrument
What happens to liquids in a mass spectrometer as it has a very good vacuum?
-liquids quickly turn to gas
What turns to gas in the vaporisation stage of mass spectrometry?
-liquids
In what stage of mass spectrometry do liquids turn to gas?
-vaporisation
What may need to be done to solid materials in order to vaporise them in a mass spectrometer?
-they may need to be heated
What may need to be heated during the vaporisation stage of mass spectrometry?
-solids
What is the purpose of the ionisation stage of mass spectrometry?
-to turn the atoms or molecules into ions
What stage of mass spectrometry turns atoms or molecules into ions?
-ionisation
What is used to turn atoms or molecules into ions during the ionisation stage of mass spectrometry?
-an ‘electron gun’
In what stage of mass spectrometry is an electron gun used?
-ionisation
What is an electron gun?
-a heated filament that gives of electrons
What is a heated filament that gives of electrons?
-an electron gun
What does the electron gun fire at the atoms or molecules of the sample gas during the ionisation stage of mass spectrometry?
-high-energy electrons
What fires high-energy electrons at the atoms or molecules of the sample gas during the ionisation stage of mass spectrometry?
-an electron gun
What does the electron gun fire high-energy electrons at during the ionisation stage of mass spectrometry?
-at the atoms or molecules of the sample gas
What are knocked off the particles of the sample gas during the ionisation stage of mass spectrometry?
-electrons
What are electrons knocked off during the ionisation stage of mass spectrometry?
-particles of the sample gas
What are produced when electrons are knocked off the particles of the sample gas during the ionisation stage of mass spectrometry?
-positive ions
How are positive ions produced during the ionisation stage of mass spectrometry?
(3)
- high-energy electrons are fired at the atoms or molecules of the sample gas
- electrons are knocked off the particles of the sample gas
- positive ions are produced
During what stage of mass spectrometry are positive ions produced?
-ionisation
During the acceleration stage of mass spectrometry what do the positive ions pass between?
-a series of negatively charged plates in the accelerator
During the acceleration stage of mass spectrometry what passes between a series of negatively charged plates in the accelerator?
-positive ions
During what stage of mass spectrometry do positive ions pass between a series of negatively charged plates in the accelerator?
-acceleration
What charge is on the plates that the positive ions pass between during the acceleration stage of mass spectrometry?
-negative
Where do the positive ions pass between the negatively charged plates during the acceleration stage of mass spectrometry?
-in the accelerator
What do the negatively charged plates attract from the mixture in the ionisation chamber during the acceleration stage of mass spectrometry?
-they attract the positive ions from the mixture
From where do the negative plates attract positive ions from in the ionisation chamber during the acceleration stage of mass spectrometry?
-from the mixture in the ionisation chamber
Where do the negative plates attract positive ions from the mixture during the acceleration stage of mass spectrometry?
-the ionisation chamber
What happens to the positive ions once they have be extracted from the mixture in the ionisation chamber during the acceleration stage of mass spectrometry?
-they are accelerated to high speeds
What are accelerated to high speeds during the acceleration stage of mass spectrometry?
-positive ions
After the positive ions have been accelerated to high speeds what passes into the analyser unit during the acceleration stage of mass spectrometry?
-a fine beam of ions
Where does the fine beam of ions pass into during the acceleration stage of mass spectrometry?
-the analyser unit
What passes into the analyser unit during the acceleration stage of mass spectrometry?
-a fine beam of ions
Why must there be a vacuum inside a mass spectrometer?
-so that the positive ions can travel through it without colliding with any air molecules
What does a good vacuum prevent positive ions colliding with?
-air molecules
What prevents positive ions colliding with air molecules when travelling through a mass spectrometer?
-a good vacuum
What are the positive ions made do in the analyser during the fourth stage of mass spectrometry?
-made to move in curved paths using a magnetic field
What are made to move in curved paths using a magnetic field during the fourth stage of mass spectrometry?
-positive ions
What is used to make the positive ions move in curved paths during the fourth stage of mass spectrometry?
-a magnetic field
What is the magnetic field used to make the positive ions move in curved paths during the fourth stage of mass spectrometry produced by?
-a powerful electromagnet
What does the powerful electromagnet do in the fourth stage of mass spectrometry?
-it produces a magnetic field
What is easily deflected in the fourth stage of mass spectrometry?
-the lighter particles
What happens to the lighter particles during the fourth stage of mass spectrometry?
-they are easily deflected
What are more difficult to deflect during the fourth stage of mass spectrometry?
-heavier particles
What happens to the heavier particles during the fourth stage of mass spectrometry?
-they are more difficult to deflect
What happens to the lighter ions during the fourth stage of mass spectrometry?
-they are pushed further of course than the heavier ions
What ions are pushed further of coarse during the fourth stage of mass spectrometry?
-the lighter ions
What is the single beam of positive ions split into during the fourth stage of mass spectrometry?
-it is split into a number of beams
What is split into a number of beams during the fourth stage of mass spectrometry?
-the single beam of positive ions
What are the ions separated according to in the fourth stage of mass spectrometry?
-according to their masses
What are separated according to their masses in the fourth stage of mass spectrometry?
-the ions
What principle does the fourth stage of mass spectrometry demonstrate?
-the principle on which mass spectrometry is based
Where do the positive ions fall during the final stage of mass spectrometry?
-on the detector
What falls onto the detector during the final stage of mass spectrometry?
-positive ions
What is the detector?
-a very sensitive instrument that responds to the number of ions hitting it
What is a very sensitive instrument that responds to the number of ions hitting it?
-a detector
By doing what does the operator of the mass spectrometer bring ions of different masses to a focus on the detector during the final stage of mass spectrometry?
-by changing the strength of the magnetic field
By changing the strength of the magnetic field what does the operator do during the final stage of mass spectrometry?
-brings ions of different masses to a focus on the detector
After the ions of different mases have been brought to a focus on the detector what is then done to the signal during the final stage of mass spectrometry?
-the signal is then amplified into a sizeable electric current and then viewed on a computer screen
What is the signal amplified into during the final stage of mass spectrometry?
-a sizeable electric current
What is viewed on a computer screen during the final stage of mass spectrometry?
-the signal which has been amplified into a sizeable electric current
Where is the signal sent to during the final stage of mass spectrometry?
-a printer
What happens when the signal is sent to the printer during the final stage of mass spectrometry?
-it is sent to a printer where a series of peaks is printed out
What is the series of peaks printed during the final stage of mass spectrometry called?
-mass spectrum
What is a mass spectrum?
-the series of peaks printed during the final stage of a mass spectrometer
What are the uses of a mass spectrometer by chemists?
4
- identify the presence of isotopes
- measure the relative abundances of isotopes
- measure relative atomic mases and relative molecular masses
- identify unknown compounds
In what two ways can electron configurations be written?
2
- the Bohr model
- in terms of energy sublevels
What does each main energy levels consist of, excluding the first?
-a number of sublevels
What consists of sublevels?
-each main energy level, excluding the first
What energy level does not consist of sublevels?
-the first
How many sublevels does the n=2 main energy level have?
-two sublevels
What main energy level consists of 2 sublevels?
-the n=2 main energy level
How many sublevels does the n=3 main energy level have?
-three sublevels
What main energy level has three sublevels?
-n=3
How many sublevels does the n=4 main energy level have?
-four sublevels
What main energy level has four sublevels?
-n=4
What is the maximum number of electrons that can be accommodated in an orbital?
-2
What type of sublevel can hold two electrons?
-an s sublevel
How many electrons can an s sublevel hold?
-2
What type of sublevel can hold six electrons?
-p sublevel
How many electrons can a p sublevel hold?
-six
In a p sublevel how many orbitals are there?
-3 p orbitals
How many electrons are contained in each p orbital of the p sublevel?
-two
How many electrons can a d sublevel hold?
-ten electrons
What sublevel can hold ten electrons?
-d sublevel
How many d orbitals are there in a d sublevel?
-five
How many electrons can each of the five d orbitals hold in a d sublevel?
-two
What does the Aufbau Principle help us get a picture of?
-how the electronic structure of an atom is built up as electrons are added to the atom
What helps us get a picture of how the electronic structure of an atom is built up as electrons are added to the atom?
-the Aufbau Principle
Why is the 4s sublevel always filled before the 3d sublevel?
-the 4s sublevel is lower in energy than the 3d sublevel
Which sublevel is 4s lower in energy then?
-3d
What sublevel is the 3d sublevel higher in energy than?
-4s
Why are there ten elements in the first row of the d-block elements?
-because the d sublevel can hold ten electrons
How many electrons can the n=3 main energy hold a total of?
-eighteen electrons (2 in the 3s sublevel, 6 in the 3p sublevel and 10 in the 3d sublevel)
What sublevels have extra stability?
-those that are exactly half filled or completely filled
What is an ion?
-an atom that has lost or gained electrons
What is an atom that has lost or gained electrons called?
-an ion
What happens to an atom that gains electrons?
-it becomes negatively charged
When does an atom become negatively charged?
-when it gains electrons
What happens to an atom that loses electrons?
-it becomes positively charged
When does an atom become positively charged?
-when it loses electrons
Who is responsible for Hund’s rule of Maximum Multiplicity?
-Friedrich Hund
What did Friedrich Hund study?
-spectra of various elements
What did Friedrich Hund put forward?
-Hund’s Rule of Maximum Multiplicity
What was Wolfgang Pauli’s deduction called?
-the Pauli Exclusion Principle
Who deducted the Pauli Exclusion Principle?
-Wolfgang Pauli
What did Wolfgang Pauli study?
-spectra
