C9 Flashcards
Describe the Periodic Table
It is a method of classifying elements, it is used to predict properties of elements
Describe the change from metallic to non-metallic character across a period
- group I is most reactive in metals, and as you go further to the right the reactivity decreases until group IV (the least reactive group). then, it increases again which makes group VII the most reactive in the non-metals
- (baisically the reactivity is like a “V”
This is because the elements on the left are metals and element on the right are non-metals (and metals have higher melting and boiling points than non-metals).
- From left to right elements change from metallic to non-metallic character
Describe the relationship between:
group number,
number of outer shell electrons,
+
metallic/non-metallic character
- atoms of elements in the same group have the same number of electrons in their outer shells (same # of valence electrons, thus the same valency)
- Down group I, elements become more reactive
- Down group VII, element become less reactive.
- Down many groups, the elements go from non-metal to metal
- Group number shows the number of electrons in the outer shell
- All of group 1 and 2 are metals, all of group 7 and 8 are nonmetals. In groups 3,4,5,6 there is a transition between metals and nonmetals
- group = group 0. they are noble gases
Describe lithium, sodium and potassium in Group I (properties of group I metals)
They are a collection of relatively soft metals showing a trend in melting point, density and reaction with water
Predict the properties of other elements in Group I, given data, where appropriate
Melting point:
- Low melting points compared to most other metals
- As you go down the group, melting points decrease
Density:
- Low densities - they will float on water
- As you go down the group, densities increase
Reaction with water:
- All react vigorously with water to create an alkaline solution and hydrogen (which is why they are called alkali metals)
- More bubbles with reaction = more vigorous reaction = more reactive alkali metal (Group I metal)
- Reactivity increases down the group (reaction becomes more vigorous)
- Down the group it is easier to lose electrons and form positive metal
ions (cations), these are formed when metals react
State the reaction of chlorine, bromine and iodine with other halide ions
A more reactive halogen will displace halide ions of a less reactive halogen
Chlorine will displace both bromide and iodide ions:
Bromine will displace iodide but not chloride ions
Iodine will not displace chloride or bromide ions
all 3 form salts with all metals
Describe the halogens, chlorine, bromine and iodine in Group VII
they are a collection of diatomic non-metals showing a trend in colour and physical state
Predict the properties of other elements in Group VII, given data where appropriate
Properties of Halogens:
-melting and boiling points increase as you go down the group
-reactivity decreases as you go down the group
-kills bacteria
-react with metals to form metal halides
Describe the transition elements
they are a collection of metals having high densities, high melting points and forming coloured compounds, and which, as elements and compounds, often act as
catalysts
Describe the noble gases, in Group VIII or 0, and explain this in terms of electronic structure
They are unreactive, monoatomic gases.
They are unreactive because their outer shells are full. This means that they are stable without having to gain or lose electrons.
State the uses of the noble gases in providing an inert atmosphere
Under normal conditions, noble gases are odourless, colourless and nonflammable.
Argon: used in lightbulbs.
Helium: used to inflate tires and balloons
Neon: used in neon lights, as it glows when electricity is passed through it
Xenon: used in photocopying.
