FINAL BUFFER Flashcards
(97 cards)
Alkali metals
Elements found in Group 1 of the periodic table
Why are they called alkali metals?
Because when reacted with water they form alkaline solutions
What are the typical poroperties of Group 1 elements?
Shiny when freshly cut, good conductors of electricity, solid at room temperature, soft
As you go down the Group 1 Elements…
their density increases and their melting point decreases and reactivity increases
Why are Group 1 elements stored in oil?
To make sure they are not exposed to oxygen which they react rapidly with
alkali metal + water =
metal hydroxide + hydrogen
How does lithium react with water?
fizzes steadily and slowly disappears
How does sodium react with water?
melts to form a silvery ball, fizzes vigourously and quickly disappears
How does potassium react with water?
immediately ignites, burns with a lilac flame and very quickly disappears
Explain the trend in reactivity in Group 1 Elements
All atoms in Group 1 have one electron in their outer shell. The easier it is for an atom of a Group 1 Element to lose its outer electron, the more reactive the element is due to forces of attraction between the negatively charged electron and positively charged nucleus.
What do Group 7 elements exist as?
diatomic molecules with weak intermolecular forces
What is fluorine at room temperature?
a pale yellow gas
What is chlorine at room temperature?
a green gas
What is bromine at room temperature?
orange-brown liquid that vapourises easily
What is iodine at room temperature?
a shiny grey-black crystalline solid that sublimes to form a purple vapour
As you go down Group 7…
density increases, melting and boiling points increase, reactivity decreases
Halogens
Group 7 elements which react with metals to produce salts
Explain the trend in reactivity for halogens
All halogens have seven electrons in the outer shell. The easier it is for a halogen atom to gain an outer electron, the more reactive the element is due to forces of attraction between the electrons and the nucleus.
Halide
a compound containing a Group 7 element and another element usually hydrogen or a metal
What happens in a halogen displacement reaction?
a halogen will displace a less reactive halogen from its halide ions in solution
Noble gases
Unreactive elements found in Group 0 of the periodic table
Why are noble gases so unreactive?
They havecomplete outer shells meaning they have no tendency to lose or gain electrons to form ions
What do noble gases exist as?
monoatomic molecules with very weak forces of attraction between them
Why do noble gases have such low boiling points?
Having weak forces of attraction between atoms means these forces are very easily overcome by heating