What is an element?
An element is a substance that cannot be broken down any further.
What were the 4 elements that the Ancient Greek recognized?
Earth, air, water, and fire
Who was the first person, in 1526, to clearly challenge the Greeks notion of 4 elements? And what elements did he propose?
Paracelsus proposed salt, sulphur, and mercury
What were alchemists interested in learning?
They were interested in learning how to make gold from base elements and find the secret to eternal life.
In 1669, what was Hennig Brand looking for, where was he looking, and what did he find instead.
Hennig was looking for gold in urine, but he found phosphorus instead.
What is another name for phosphorus?
Icy Noctoluca
What did Robert Boyle make when he added sulfur to phosphorus?
He made the first match.
What did Robert Boyle write?
He wrote "The Skeptical Chemist"
What blind alley did Johann Becher lead the scientific community into?
He contended that there was a substance, called phlogiston, that caused fire to burn and reduce substances to ash.
What new element did Henry Cavendish discover and was it flammable?
He discovered Hydrogen gas which was very flammable.
In 1774, which scientist studied carbon dioxide at a brewery and later discovered Oxygen as an elemental gas?
Joseph Priestly
Which French scientist was fanatical about precise measurements?
Antoine Lavoisier
State the Law which Antoine Lavoisier made which guides the balancing of chemical equations?
The Law of the conservation of mass states " Matter can neither be gained or lost, only changed".
What happened to Antoine Lavoisier that cut short his career?
He lost his head to French revolutionaries.
How many elements did Antoine Lavoisier classify and what 4 groups did he classify them into?
19 elements
Gasses
Non-metals
Metals
Earth
What did Humphrey Davy do, in 1807, to isolate the element Potassium from Potash?
He invented a new field in chemistry called electrochemistry which used electricity to separate elements from compounds.
How many elements were there by 1829?
55 separate elements
Who proposed that elements were made up of building blocks called atoms?
John Dalton in 1805
What 3 scientists were responsible for demanding all elements had precise atomic weights?
John Dalton, Jöns Jacob Berzelius and Stanislao Cannizzaro
What pattern did Johann Wolfgang Döbereiner see with some elements?
He saw patterns of 3 called triads (alkali metals for example)
What scientist was responsible for seeing the patterns for the rule of 8 (octet rule)?
John Newland
Who developed the first table of elements on February 17, 1869?
Dmitri Medeleev
What 2 scientists were responsible for the science of spectral chemistry?
Robert Bunsen and Paul Emile Lecoq
What did Pierre Janssen and Norman Lockyer discover using spectral chemistry?
Where was it discovered?
They discovered Helium on the sun.
Who discovered the no-reactive noble gasses?
William Ramsay
In 1909, what 2 atomic scientists are responsible for developing a working model of the atom?
Ernest Rutherford and Niels Bohr
What scientist was responsible for identifying elements by the number of their protons (atomic number)?
Henry Moseley
What did Justus von Liebig and Friedrich Wöhler discover about compounds?
They discovered isomerism. Molecules with the same molecular formula, but different structures.
How did Smithson Tennent prove that diamonds were made of Carbon?
He burned one and produced carbon dioxide.
Which 2 scientists formulated the theory of chemical bonds?
Archibald Scott Couper and Friedrich Kekulé
Wallace Carothers successfully drew off a fibre from the interface of two liquids: hexane-1,6-diamine and decanedioyl-dichloride. What was that fibre?
Nylon
What French and Polish scientists pioneered radioactive chemistry?
Henri Becquerel and Marie Curie
Who discovered the Neutron in 1932?
James Chadwick
What scientist was first responsible for bombarding atoms with neutrons in order to make elements that were heavier than Uranium?
Enrico Fermi
What woman scientist was responsible for proving Einstein's famous equation E=mC^2?
Lise Meitner
What did Enrico Fermi do in 1942?
He made the first successful nuclear chain reaction while working on the Manhattan Project.
What synthetic element did Edwin McMillian and Phillip Ableson create?
Plutonium, used in the bomb that was dropped on Nagasaki, Japan.
