1.6 The Periodic Table Flashcards
What are s-block elements and their characteristics?
S-block elements are metals found in Group 1 and 2 that form basic oxides, are reducing agents, and have a melting point that decreases down the group.
What are p-block elements and their characteristics?
P-block elements are non-metals that form acidic oxides, are oxidising agents, and have a melting point that increases down the group.
What does it mean if a species increases in oxidation number?
It is said to be oxidised.
What does it mean if a species decreases in oxidation number?
It is said to be reduced.
What is an oxidising agent?
A species that accepts electrons and becomes reduced in the process.
What is a reducing agent?
A species that donates electrons and becomes oxidised in the process.
What is a redox reaction?
A reaction where both oxidation and reduction take place.
How do you carry out a flame test?
Dip a wire loop into concentrated hydrochloric acid, hold in a roaring flame to remove contaminants, dip in the compound to be tested, and observe the color shown by the compound.
What forms when s-block metals come into contact with oxygen or air?
Oxides are formed.
What is the general equation for Group 1 reactions with oxygen?
4M + O2 –> 2M2O
What is the general equation for Group 2 reactions with oxygen?
2M + O2 –> 2MO
What do Group 1 and 2 elements generally form when they react with water?
Hydroxides, with hydrogen released, leading to effervescing.
What is the general equation for Group 1 reactions with water?
2M + 2H2O –> 2MOH + H2
What are the solubility characteristics of Mg, Ca, Sr, and Ba with hydroxides, carbonates, and sulfates?
Mg + OH/CO3/SO4 = Insoluble salt
Ca + OH = Sparingly insoluble salt
Ca + CO3 = Insoluble salt
Ca + SO4 = Moderately soluble salt
Sr + OH = Moderately soluble salt
Sr + CO3 = Insoluble salt
Sr + SO4 = Sparingly soluble salt
Ba + OH = Soluble salt
Ba + CO3/SO4 = Insoluble salt
How does reactivity change down Group 1 and Group 2?
Reactivity increases down the group due to outer electrons being further from the nucleus and more easily lost.
What happens to Group 2 carbonates when heated?
They undergo thermal decomposition to produce an oxide and carbon dioxide gas.
How does thermal stability change down Group 2?
Thermal stability increases down Group 2.
How does the solubility of Group 2 hydroxides change down the group?
It increases down the group.
How does the solubility of Group 2 sulfates change down the group?
It decreases down the group.
What character do all Group 1 and Group 2 oxides and hydroxides have?
They are basic in character.
How does base strength change down Group 1 and Group 2?
Base strength increases down the group.
What happens to reactivity, oxidising power, and volatility down Group 7 halogens?
They decrease down the group.
How does volatility change down Group 7?
Volatility decreases down the group due to stronger intermolecular forces.
What happens to reactivity in Group 7 as you go down the group?
Reactivity decreases as oxidising power decreases.
What do all halogens do when they react with sodium metal?
They produce a sodium halide.
What is the visual indication of sodium igniting during halogen reactions?
A bright orange flame and a white solid halide are produced.
What is the role of chlorine gas in drinking water?
It kills dangerous bacteria and viruses, preventing outbreaks of serious diseases.
What is the role of fluoride in toothpaste and water?
It strengthens tooth enamel and helps prevent decay, as well as strengthening bones and preventing osteoporosis.
