C4.1 Flashcards
elements in Group 1 of the periodic table
alkali metals
Define a catalyst
a substance that increases the rate of reaction, without being used up, by lowering the activation energy needed
Define crystalline
the structure of substances in the solid state that have particles arranged in a giant lattice
density
mass per unit volume,
measured in g/cm3 or kg/m3.
An object with high density is dense and feels heavy for its size
Define a displacement reaction
reaction in which a more reactive element displaces a less reactive element from it compounds
Noble gases are the name of elements in which group of the periodic table
Group 0, 8 or 18
Name of negative ions made from group 7 elements
halide ion
What are elements in Group 7 of the periodic table called?
halogens
What are monatomic elements
existing as single atoms, such as the noble gases
Define reactivity
the tendency of a substance to take part in chemical reactions
What are elements in the block of the periodic table between Groups 2 and 3 called
transition metals
describe trends in the physical properties of the Group 1 elements.
The alkali metals:
1 - are soft (they can be cut with a knife)
2 - going down group 1, the melting point decreases.
3 - Generally low densities. The first three (lithium, sodium and potassium float on water.
What happens when Group 1 elements react with water.
universal indicator turns solution blue or purple
Metal fizzes and dissolves (or catches fire)
What is the general balanced equation for the reactions of the Group 1 elements with water
2M(s) + 2H2O(l) → 2MOH(aq) + H2(g)
Alkaline metal + water → metal hydroxide + hydrogen
describe trends in the physical properties of the Group 7
The melting points and boiling points of the halogens increase going down group 7, and their colour gets darker.
use knowledge of electronic structures to explain in detail the trend in reactivity of the Group 1 elements.
A change like this, where an electron is lost, is an example of oxidation.
The ions formed have a stable electronic structure, like a noble gas from Group 0.
The reactivity of Group 1 elements increases as you go down the group because:
the atoms get larger as you go down the group
the outer electron gets further from the nucleus as you go down the group
the attraction between the nucleus and outer electron gets weaker as you go down the group - so the electron is more easily lost
Write the general balanced chemical equations for the reactions of Group 7 (IUPAC Group 17) elements with metals.
The halogens react with metals to produce salts
describe the trend in reactivity of the Group 7 (IUPAC Group 17) elements.
The halogens become less reactive going down group 7.
use knowledge of electronic structures to explain in detail the trend in reactivity of the Group 7 (IUPAC Group 17) elements.
Atoms of group 7 elements all have seven electrons in their outer shell.
What is the order of reactivity of the halogens to explain the outcome of a displacement reaction.
A more reactive halogen can displace a less reactive halogen from solutions of its salts.
F > Cl > Br >I