Periodicity 2 notes

What type of element is silicon classified as and what is its main property?

Silicon is classified as a metalloid and can conduct electricity to a certain extent.

Which elements in period 3 are non-metals and cannot conduct electricity?

Phosphorus (P), sulfur (S), and chlorine (Cl) are non-metals that cannot conduct electricity.

What is the oxidation state of sodium?

The oxidation state of sodium is 1+.

What are the products of the reaction of sodium with water?

2NaOH (aqueous) and H2 (gas).

What is the reaction speed and pH when sodium reacts with water?

The reaction is vigorous and has a pH of 14.

What is the oxidation state of phosphorus?

The oxidation state of phosphorus is 3-.

What is the symbol equation for the reaction between magnesium and steam?

Mg(s) + H2O(g) → MgO(s) + H2(g).

What is the general trend in the melting point of period 3 oxides across the period?

Melting points tend to decrease due to an increase in intermolecular van der Waals forces between larger molecules.

What type of bonding character does aluminum oxide exhibit?

Aluminum oxide exhibits ionic bonding with covalent character.

What is the main property of silicon dioxide?

Silicon dioxide has a macromolecular/giant covalent structure and high melting point.

What happens to sodium oxide when it reacts with water?

Sodium oxide produces an alkaline solution with a pH of approximately 14.

Which metal oxide is insoluble in water?

Aluminum oxide (Al2O3) and silicon oxide (SiO2) are insoluble.

What is the product of the reaction of magnesium oxide with hydrochloric acid?

The product is magnesium chloride (MgCl2) and water (H2O).

How does aluminum chloride behave when dissolved in water?

It forms aluminum hydroxide and releases hydrogen ions.

What is the overall equation for the neutralization reaction between phosphoric acid and sodium hydroxide?

3NaOH(aq) + H3PO4(aq) → Na3PO4(aq) + 3H2O(l).

What is the oxidation state of sulfur in sulfur dioxide?

The oxidation state of sulfur in sulfur dioxide (SO2) is 4+.

What are the acidic oxides mentioned in the notes?

Phosphorus oxide (P4O10) and sulfur dioxide (SO2) are examples of acidic oxides.