Atomic structures Flashcards
What is a mixture?
When two or more elements or compounds are mixed together but aren’t chemically bonded
What is an element?
A pure substance made up of only one type of atom
What is a compound?
A substance that is made up of two or more atoms which are chemically bonded together
What does soluble means?
When something can dissolve
What does insoluble mean?
When something is unable to dissolve
Name the subatomic particles
Electron
Proton
Neutron
What does the mass tell us?
Protons+ neutrons
What does the atomic number tell us?
Protons which is the same as electrons
What is periodic table arranged in?
Atomic number (protons)
What is an isotope?
A version of the same element but with a different number of neutrons
What is the relative mass of a proton?
1
What is the relative mass of a electron?
Very small
What is the relative mass of a neutron?
1
What is the electric charge of a proton?
+1
What is the electric charge of a electron?
-1
What is the electric charge of a neutron?
0
When did Mendeleev organise the periodic table?
1869
What did Mendeleev organise the periodic table according to?
To the element’s atomic mass
How did Mendeleev group the elements?
Corresponding to their chemical properties
Why did Mendeleev place the alkaline metals in one group together?
Because they had similar properties
Why are transition metals placed between groups 2 and 3?
Because they have a similar number of electrons in their third shell
Why did Mendeleev leave gaps?
For missing elements
How created the table we use today?
Henry Mosely
When did Henry Mosely produce the table we use today?
1914
How did Mosely organise the elements?
According to their atomic number
What did Mosely add to the table?
The noble gases
Who first organised the periodic table according to their atomic mass?
John Newland
When was the electron discovered and who by?
J.J Thompson and in 1897
What did J.J Thompson create?
The plum pudding model- he imagined the atom was positively charged with electrons stuck in it
Who tested J.J Thompson’s theory and when?
1991 Rutherford
How did Rutherford test Thompson’s theory?
He fired particles at atoms however some bounced off funny not centred
When was the proton and neutron discovered and by who?
By Chadwick in 1932
What reaction would take place with the hot tungsten was surrounded by air?
It would react with oxygen and burn out
What is Rn used for?
Radiotherapy
What is Kr and Xe used for?
Lasers
What are metals?
They losers because they want to react to achieve a full outer shell so they have to give away their electrons
Name some properties of a metal
Good conductor of heat and electricity
High density
Strong
solid
Name some properties of a non metal
Poor conductor of heat and electricity
Low density
Soft
Solid, liquid or gas
What elements are the halogens?
Chlorine, fluorine, bromine, iodine and astatine
What metals do the halogens react with ?
Alkali metals to form halide ions with a charge of -1
What happens when you go down group 7?
The reactivity decreases
Why does the reactivity of group 7 decrease as you go down?
As you go down the group you gain shells and for non metals to react they need to gain electrons. So it is harder to gain electrons because it is further away from the nucleus
What happens when you go down group 1?
The reactivity increases
Why does the reactivity of group 1 increase as you go down?
Because for metals to gain a full outer shell they lose electrons so when you go down the group the number of shells increase so the nucleus attraction is weaker. So it is easier to lose electrons
What are the key properties of the alkali metals?
Low density
Soft
Float
What do alkali metals react with?
Oxygen and hydrogen to form a hydroxide
What is displacement?
When a more reactive metal displaces a less reactive metal
What is oxidation?
Loss of electrons
What is reduction?
Gain of electrons
Acid + metal equals
Soluble salt + hydrogen
What type of ion does all acids contain?
Hydrogen ions
What happens when acids are dissolved in water?
They fully ionise to release H+ ions into a solution, making it strong
Insoluble base (oxide) + acid equals
Soluble salt + water
Insoluble salt (carbonate) + acid equals
Soluble salt + water + carbon dioxide
