C1 - Atomic Structure and the Periodic Table Flashcards
What are the subatomic particles in an atom?
Neutron
Proton electron
What is the size of an atom?
0.1 nm
What is the relative charge of a neutron?
0
What is the relative charge of a proton?
+1
What is the relative charge of an electron?
-1
What is the relative mass of an electron?
Very small
What is the relative mass of a proton?
1
What is the relative mass of a neutron?
1
What is the atomic number?
The number of protons
What is the mass number?
The number of protons and neutrons
How many electron does an atom have?
The same as protons
What is the overall charge on an atom?
0
What are isotopes?
Atoms that have the same proton number but different number of neutrons
What is an element?
Substances made up of atoms with the same atomic number
How do you calculate the relative atomic mass?
Sum of (isotope abundance x isotope mass number) / total abundance
What is a compound?
A substance made up of two or more different elements chemically bonded together in fixed positions
What is a molecule?
When two or more non-metals are covalently bonded
Why does a chemical reaction need to be balanced?
Because there need to be an equal number atoms on both sides
What is a mixture?
A substance made up of different elements or compounds that are not chemically bonded to each other and can be serrated by physical methods.
How do we separate compounds?
By chemical reaction
In a mixture, do the substances keep their properties or are they changed?
They keep
Why should we draw the baseline in paper chromatography with pencil?
Because the pencil contains graphite which is not soluble in water so it will not smudge the results
Which substances in a sample are moved further in paper chromatography?
The ones that are more soluble in the solvent
Which substances in a sample remain at the baseline?
The insoluble substances
Why does the solvent need to be below the baseline?
Before the paper can even suck up the solvent, the sample will all dissolve in the solvent and nothing will rise up
What is the solvent front?
The distance that the solvent has travelled
How do you calculate the Rf value?
Distance travelled by the spot / distance travelled by the solvent
What will change the Rf value of a substance?
The solvent used
If you have a pure substance, how many spots are expected to be seen in the chromatography?
one
What are the different physical separation techniques?
Filtration, simple and fractional distillation, chromatography, crystallisation, evaporation
What is filtration used for?
To separate insoluble says from liquids
What is the solid left on the filter paper called?
Residue
What is the liquid that goes through the filter paper called
Filtrate
What is evaporation used for?
To separate soluble salts from liquids
Describe the developments in the atomic model
Atoms are solid spheres Plum pudding model Nuclear model Bohr's model Nucleus has protons Chadwick discovered neutrons
Why is the solid sphere model incorrect?
The atom is not a solid sphere but made up of loads of empty space
Why is the plum pudding model incorrect?
Electrons are not inside the nucleus
Why is the nuclear model incorrect?
Because atoms contained shells
What is another word for shell?
Energy level
How many electrons can go in the first, second and third shell?
2
8
8
What is the lowest shell?
The first one
The one that is closest to the nucleus
How were the elements in the old periodic table arranged?
According to increasing atomic weight/mass
How did Mendeleev arrange the elements in this Table of Elements?
He arranged elements according to their properties as well as atomic weight
Why did Mendeleev leave gaps in his table?
Elements were not discovered yet
What explained why elements cannot be strictly ordered by atomic weight?
The discovery of isotopes
How are the elements in the modern periodic table arranged?
Increasing proton/atomic number
In Groups and Periods
What does the Group tell you about the electronic structure of an element?
How many outer shell electrons it has
What does the Period tell you abut the electronic structure of an element?
The number of shells
Why do elements in the same group have the same chemical properties?
Because they have the same number of electrons in the outer shell
Do metals form positive or negative ions?
Positive
Do non-metals form positive or negative ions?
Negative
How do metals gain a full outer shell?
By losing electrons
How do non-metals gain a full outer shell?
By gaining electrons
What does it mean when metals are more reactive?
They can lose the electrons more easily
What does it mean when non-metals are more reactive?
They can gain electrons more easily
Metals get more reactive towards…
as you go down the group
Non-metals get more reactive towards…
as you go up the group
What is the appearance of metals like?
Shiny
What is the appearance of non-metals like?
Dull
What is the strength of metal like?
Strong but malleable
What is the strength of non-metal like?
Brittle
What is the melting and boiling points of metals like?
High
What is the melting and boiling points of non-metals like?
Low
What is a better conductor of electricity, metals or non-metals?
Metals
Name one exception of a metal that has low melting and boiling points
Mercury
How does the reactivity of the Group 1 elements change as you go down the group?
Increases
How do the melting and boiling points of the Group 1 elements change as you go down the group?
Decrease
How does the relative atomic mass of the Group 1 elements change as you go down the group?
Increase
Name properties of the Group 1 metals
They are softer than other metals
They are very reactive
They have lower melting points
What is the charge on an ion formed by a Group 1 element?
1+
What are the products of alkali metals with water?
Metal hydroxide + hydrogen
What are the products of alkali metals with chlorine?
Metal chloride
What is the product of the reaction of alkali metals with oxygen?
Metal oxide
What is another word for the Group 0 elements?
Noble gases
Why are noble gases so stable?
They have a full outer shell of electrons
How do the boiling points of Group 0 elements change as you go down the group?
Increases
What is the state of Group 0 elements at room temperature?
Gases
What is the colour of the noble gases?
Colourless
What is the appearance of fluorine like?
Yellow gas
What is the appearance of chlorine like?
Green gas
What is the appearance of iodine like?
purple vapour
What is the appearance of bromine like?
red-brown liquid
How does the reactivity of the Group 7 elements change going down the group?
Decreases
How does the molecular mass of the Group 7 elements change going down the group?
Increases
How do the melting and boiling points of the Group 7 elements change going down the group?
Increase
What is another word for Group 7 elements?
Halogens
Are halogens monoatomic or diatomic?
Di
Are noble gases mono or di atomic?
Mono
What type of a bond do halogens form with non-metals?
Covalent
What type of bond do halogens form with metals?
Ionic
What is the charge on the ion formed from a halogen?
1-
What is a displacement reaction?
When a more reactive halogen/element replaces a less reactive one
