The Periodic Table Flashcards
Who was Mendeleev
Mendeleev was a Russian scientist. He came up with the idea of organising the elements in a table.
What was special about Mendeleev’s first table of elements
Left gaps for undiscovered elements
Arranged elements in groups and periods
Separated metals
Arranged elements in atomic mass.
Why was leaving gaps in Mendeleev’s design so genius?
It allowed him to predict the properties of the undiscovered elements accurately.
How is the modern periodic table different to Mendeleev’s original design
No gaps
Noble gases
Elements in atomic order
Actinides and lanthanides
Define element
A substance which is made up of one type of atom and cannot be broken down into anything simpler by chemical means
What is a period
The horizontal rows in the periodic table
What is a group
A vertical column in the periodic table
Name properties of metals
Good conductors of electricity and heat
High melting and boiling points
All solid at room temperature (except mercury)
Shiny
Malleable
Ductile
Sonorous
Where is the divide between metals and non metals on the periodic table
Aluminium steps down to Polonium
Which elements are gases at room temperature
Nobel gases
Nitrogen
Oxygen
Fluorine
Chlorine
Which elements are liquids at room temperature
Bromine
Mercury
What do elements in each group have in common with each other
They all have the same amount of electrons in the outer shell giving them same properties
What elements are in group 1
Alkali metals
What trends do elements in group 1 follow down the group
Bigger atoms
More dense
Even softer to cut
Lower melting/boiling point
More reactive
Why are the alkali metals more reactive down the group
Reactivity increases because of the 1 electron needing to be lost. The further away the outer shell it the easier it is to lose. The easier to lose the more violent reaction.
Which elements are less dense than water
First 3 in group 1 (lithium, sodium and potassium)
What is the ionic equation for group one metals
M—-> M+➕e-
What observations are made when lithium is added to water
Metal floats, fizzing occurs, heat is released, moves about the surface and disappears with a smoke and crackle/explosion.
What observations are made when sodium is added to water
Metal floats, fizzing occurs, heat is released, melts into a ball, moves about surface and disappears with a smoke and crackle/explosion
What can be observed when potassium is added to water
Metal floats, fizzing occurs, heat is released, a lilac flame, moves about the surface and disappears with a smoke crackle/explosion.
What are elements in group 2 known as
Alkaline Earth metals
What are elements in group 7 known as
Halogens
Why are group 1 metals stored safely in oil
To stop oxidisation of elements as they will quickly.
Why does the boiling points of the noble gases increase down the group
The increased strength of wan der waal forces.
What are the element in group 0/8 known as
The noble gases
What is fluorine’s appearance at room temperature
Pale yellow gas
What is chlorines appearance at room temperature
Pale green gas
What is bromines appearance at room temperature
Red-brown liquid
What is iodines appearance at room temperature
Dark grey solid gives off purple vapour
What are trends for halogens down the group
Bigger atoms
Less soluble
Increasing melting/boiling point
What is the test for chlorine
Turns damp blue litmus paper / damp universal indicator paper red then bleaches it white.
What is the ionic half equation for formation of halogen ions us chlorine as example
Cl2 ➕ 2e- —-> 2Cl-
How are the transition metals different to those in group 1
Higher melting points
Higher density
Less reactive with water
Form ions with different ions (e.g Iron III and iron II)
Form coloured compounds
What compounds colour the transition metals
Oxide -black
Carbonate -green
Sulfate- blue
Recall the observation when solid iodine sublimes
I2(solid) —-> I2(gas) purple vapour
