3.2.1 Periodicity

Equation of Na and Oxygen heated

4Na (s) + O2 (g) -> 2Na2O (s)

How do Na, Mg and P react with oxygen

vigorously

Reaction of Mg and Oxygen heated

2Mg (s) + O2 (g) -> 2MgO (s)

What colour is the flame Na, Mg and Al burn in oxygen

bright white

What is the product of Na and Mg with oxygen

White solid

What is the product of Al and Si with oxygen

white powder

Equation Al reacting with Oxygen, with powdered Al

4Al (s) + 3O2 -> 2Al2O3 (s)

How does Al react with oxygen

Fast

Equation of Silicon and Oxygen, powdered Si and heated strongly

Si (s) + O2 (g) -> SiO2 (s)

How does Silicon react with oxygen

slowly

What colour is the flame of silicon and oxygen

Bright white sparkles

What is the product like of phosphorus and oxygen

White clouds

Equation phosphorus and oxygen, heated

4P (s) + 5O2 (s) -> P44O10 (s)

What is the flame like with phosphorus and oxygen

yellow or white flame

Reaction of sulfur and oxygen, with powdered sulfur heated

S (s) + O2 (g) -> SO2 (g)

how does sulfur react with oxygen and what colour flame

gently, blue flame

What is SO2

toxic

How does sodium react with cold water

vigorously

Equation of Sodium and cold water

2Na (s) + 2H2O (l) -> 2NaOH (aq) + H2 (g)

Observations when sodium reacts with cold water

melts into a ball, gives off hydrogen gas, moves across water surface

What is the pH of the solution formed when sodium reacts with cold water

pH 14 (strongly alkaline) due to sodium hydroxide

How does magnesium react with cold water

extremely slowly

Equation for magnesium reacting with cold water

Mg (s) + 2H2O (l) -> Mg(OH)2 (aq) + H2 (g)

What is the pH of the solution formed from magnesium and oxygen

pH 9-10 (weakly alkaline) as magnesium hydroxide is slightly soluble

How does magnesium react when heated with steam

vigorously

Equation for reaction between magnesium and steam

Mg (s) + H2O (l) -> MgO (s) + H2 (g)

How does atomic radius change across period 3

decreases

How does first ionisation energy change across period 3

increases

Bonding and structure of Na, Mg and Al

metallic, giant metallic

bonding and structure in silicon

covalent, giant covalent

bonding and structure in P, S and Cl

covalent, simple molecular

structure of Ar

simple molecular

Why does melting point increase from Na to Al

stronger metallic bonding as Al can donate 3 electrons to the sea of delocalised electrons and has stronger, 3+ ions

Why does silicon have the highest melting point

Giant molecular structure with 4 covalent bonds per atom

Why does the melting point decrease from P to Ar

simple molecules have weak VDW forces between them which are easy to break. S8 has a higher MP than P4 as it is a larger molecule.