C2 Periodic Table Flashcards
Why ordering of elements changed overtime
New elements were being found and scientists needed to rearrange them by relative atomic mass
How the electronic structure of metals and non-metals are different
Atoms of metal give away electrons to form positive ions
Atoms of non-metal gain electrons to form negative ions
How the electronic structure of metals and non-metals affects their reactivity
If an atom has more electrons than protons its reactivity increases
How electronic structure is linked to the periodic table
The number of electrons in outermost shell depends on the group number the element is in
How to use the periodic table to predict reactivity of elements
For metals reactiviy increases down a group
Reactivity decreases moving left to right along a period
Why are noble gases unreactive
The atoms of noble gases already have complete outer shells so they have no tendency to lose, gain or share electrons
How to predict which ions are stable
How easily an element can achieve a full outer electron shell
Properties of group 1 metals
Soft
Reactive
Low melting points
Good conductors of heat and electricity
Low density
Why elements in group 1 react similarly
They all have 1 electron in their outer shell
Why do the first 3 elements of group 1 float on water
Less dense than water
Equation for group 1 metals react with water
2X(s) + 2H2O(s) —> 2XOH(aq) + H2(g)
How you can show that hydrogen and metal hydroxides are made when Group 1 metals react with water
Hydroxides dissolve in water to form alkaline solutions
They are purple showing they are strongly alkaline
How Group 1 metals are stored and the safety precautions used when dealing with them
Stored in mineral oil or kerosene
Do not expse to air or water
How to recognise a halogen displacement reaction
Reaction mixture turns darker and iodine solution forms
Why elements in group 7 react similarly
Same number of electrons in outer shell
Main properties of halogens
Form negative anions
More dense as go down group
Poor conductors of heat and electricity
Brittle
How to complete a halogen displacement reaction
2 drops potassium chloride to each 3 dimples in column 1 of tile
2 drops potassium bromide solution to each of 3 dimples in column 2
2 drops potassium iodide solution to each of 3 dimples in column 3
What happens in halogen displacement reaction
The more reactive halogen atoms oxidise the less reactive halide ions
causing halide ions to lose electrons and form halogen atoms
Trend in reactivity group 1 metals
Increases as you go down the group
Reactivity of group 7
Decreases as go down the group
Why group 1 reactivity increases as go down the group
As go down the group
Atoms get larger
Outer electron gets further from nucleus
Attraction between nucleus and outer electron gets weaker so electron is easily more lost
Why group 7 reactivity decreases as go down the group
As you go down the group
Atomic mass of halogens increases
Increases in electron shells
Atoms get larger as go down the group therefore attraction of outer electron to nucleus decreases as you go down group 7
Trend in group 1 boiling point
Decreases
Why group 1 boiling point decreases as go down the group
As go down the group there are more protons, electrons, neutrons and energy levels to the atoms
Atoms get larger
As atom increase in size attractive forces decrease since internuclear distance increases
This leads to lower boiling and melting temperatures
Trend in group 7 boiling points
Increases
Why trend in boiling point increases as you go down group 7
Atoms increase in size as they gain electron shells
Intermolecular forces are stronger
More energy required to break these forces
so higher boiling and melting points as go down the group
Halogens have covalent bonding
How to use nuclear model to explain how the outer electrons experience different levels of attraction to the nucleus
Higher effective nuclear charge causes greater attractions to electrons
Properties of transition metals
Hard
Strong
High melting boiling points
Good conductors of heat and electricity
Dense
Use of transition metals
Iron used to make steel used to build buildings
Copper used for coins
Why mercury is not a typical transition element
Neither the atom or its cations posses an incomplete d-subshell
Why Group 1 metals have different properties compared to transition metals
Transition metals react slowly or not at all
Why can we be confident there are no missing elements in the first 10 elements of periodic table
Element is identified with the number of protons in nucleus
Any atom with 6 protons is carbon it cannot be anything else
Patterns in periodic table
Atomic radius
Electronegativity
Metallic character
Why elements in same group react the same way
Similar number of valence electrons
Metal and non-metal ions
Metal atoms lose electrons to form positive ions
Non-metal atoms gain electrons to form negative ions
What happens when group 1 metals react with water
Reacts vigorously to produce hydrogen gas and metal hydroxides
What happens when group 1 metals react with chlorine
React vigorously to form white metal chloride salts
What happens when group 1 metals react with oxygen
They react with oxygen to form a metal oxide
Lithium reacts with oxygen to form lithium oxide (Li2O)
2 differences between the physical properties of group 1 metals and transition metals
Group 1 metals are malleable and ductile
2 differences between the chemical properties of group 1 metals and transition metals
Higher melting point
Less reactive
Similarities between the properties of group 1 metals and transition metals
Good conductors of heat and electricity
Easily oxidised to form cations
React with water
Colour of fluorine, chlorine poisonous gases
Fluroine - yellow
Chlorine - dense green
Colour of bromine (poisonous) and iodine
Bromine - Red-brown liquid
Iodine - dark grey crystalline solid or purple vapour
What happens to relative atomic masses of halogens as you go down the group
Higher relative atomic masses
Structures of compounds formed
Ionic
What do group 0 elements exist as
Monotomic gases
Monatomic gases
Single atoms not bonded to each other
What state are group 0 at room temperature
Colourless gases
Why does boiling point increase as you go down group 0
Due to an increase in number of electrons in each atom leading to greater intermolecular forces
Trend reactivity in group 0
Noble gases are unreactive
Formula sodium carbonate
Na2CO3
How were elements arranged periodic table early 1800s
Atomic weight
Which were the 2 obvious ways to categorise elements
Physical and chemical properties
Atomic weight
Where does the name periodic table come from
The periodic table got its name from how elements are arranged in rows called periods
Why were early periodic tables not complete and some elements placed in wrong group
Because elements were placed in order of atomic weight
1869 what order did Dmitri Mendeleev order elements
Order of atomic weight
1869 what order did Dmitri Mendeleev order elements
Order of atomic weight
Why did Dmitri Mendleev leave gaps in periodic table 1869
To make sure elements with similar properties stayed in same groups
Some of these gaps indicated existence of undiscovered elements elements and allowed Mendeleev to predict what their properties might be
Why was discovery of isotopes in the 20th century important for Mendeleev
It confirmed Mendeleev was correct to not place elements in a strict order of atomic weight but to also take account of their properties
John Newlands 1864
Noticed periodicity based on elemental mass and sorted elements by mass 1864
Law of octaves
Every 8th known element was similar
Which properties of elements did Dmitri Medeleev predict before they were discovered
Scandium
Gallium
Technetium
Germanium
Who was Dmitri often referred to as
“Father of the periodic table”
What is the periodic table arranged in
Order of atomic number
Word equation of group 1 elements react with water
Lithium + water ———–> Lithium hydroxide + hydrogen
Sodium + water ———–> sodium hydroxide + hydrogen
Observations when lithium reacts with water
Slow reaction
Lithium doesn’t melt
Fizzing
Observations when sodium reacts with water
Sodium melts
Hydrogen released catches fire and causes the ball to dash across surface
Observations when potassium reacts with water
Burns with lilac coloured flame
Melts into shiny ball that dashes around surface
State of bromine at 0° and 100°
0° - liquid
100° - gas
Colour change when chlorine reacts with sodium bromide
Colour at start - colourless
Colour at end - brown
2 properties of transition metals that make them suitable for cutting tools
High melting point (can withstand high temperatures)
Hard
Why transition metal oxides are added to pottery glazes
Colour
79
Br
35
Number of neutrons?
35 = number of protons
79 - 35 = 44 = number of neutrons
