# data[].attributes.headline
Reaction of silver halide precipitates with ammonia 

# data[].attributes.subject
Reaction of silver halide precipitates with ammonia 

# data[].attributes.headline
With cold dilute sodium hydroxide (NaOH)

# data[].attributes.subject
With cold dilute sodium hydroxide (NaOH)

# data[].attributes.body
Cl2 (aq), Br2 (aq), and I2 (aq) will react with cold NaOH.
-> The colour of the halogen solution will fade to colourless.
-> E.g: Cl2 (aq) + 2NaOH (aq) ® NaCl (aq) + NaClO (aq) + H2O (l)

# data[].attributes.headline
Reaction with hot concentrated sodium hydroxide (NaOH) 

# data[].attributes.subject
Reaction with hot concentrated sodium hydroxide (NaOH) 

# data[].attributes.body
With hot alkali, disproportionation occurs
3Cl2 (aq) + 6NaOH (aq) -> 5NaCl (aq) + NaClO3 (aq) + 3H2O (l)

# data[].attributes.body
to form hydrogen halides
-> e.g. I2 (g) + H2 (g) -> 2HI (g)

# data[].attributes.body
decreases as increase in distance between the nucleus and valence electrons lead to a weaker attraction to the valence electrons

# data[].attributes.body
increases as increase in protons across the period lead to stronger attraction to the valence electrons

# data[].attributes.body
increases due to increase in the electron shells and the valence electron are shielded by more electron shells down the group

# data[].attributes.body
decreases as nuclear charge is higher and electrons are more attracted to the nucleus

# data[].attributes.body
same number of valence electron, increase in number of electron shells

# data[].attributes.body
number of electron shells remain the same, proton number increase, number of valence electrons increase

# data[].attributes.body
form halides and hypohalides.
-> E.g: Cl2 (g) + H2O (l) → HCl (aq) + HOCl (aq)

* fluorine (F2) is so electronegative, it can displace oxygen from water.

# data[].attributes.body
Beryllium is the weakest reducing agent and has the lowest oxidization.

# data[].attributes.body
Barium is the strongest reducing agent and has the highest oxidization.

# data[].attributes.body
loses electrons to other substances in a redox reaction and gets oxidized to a higher oxidation state

# data[].attributes.body
occurs when a halogen with strong oxidizing agent will displaces a halogen that has a lower oxidizing power from one of its compounds.
-> e.g: F2 + 2HBr -> 2HF + Br2

# data[].attributes.body
Group 2 metals form cations with a charge of +2 by losing 2 electrons.

# data[].attributes.body
going down the group, lower tendency to be reduced, weak oxidizing agent

# data[].attributes.body
Group 2 metal is soft and silver which is harder and denser than group 1 metals

# data[].attributes.body
The melting and boiling point of the halogens increases down the group.

# data[].attributes.body
going down the group, Van der Waals forces between molecules are stronger

# data[].attributes.body
physical state change from gas to solid down the group

# data[].attributes.body
become less reactive going down the group.

# data[].attributes.body
decomposes on heating to produce Group 2 Oxide + CO2
- metal ions are bigger down the group (same charge) -> charge density dec. down the group -> carbonate ion less polarised -> thermally stable down the group

# data[].attributes.body
exist as diatomic molecules

# data[].attributes.body
Beryllium is the least reactive

# data[].attributes.body
Radium is the most reactive

# data[].attributes.body
becomes more reactive as it goes down due to the loss of 2 electron on the outer valence electron shell.

# data[].attributes.body
ALL elements (except Be & Mg - least reactive) form metal hydroxide + H2
- Group 2 Hydroxides are more soluble down the group -> Hydroxides produced make water alkaline
X (s) + 2H2O (i) -> X(OH)2 (aq) + H2 (g)

# data[].attributes.body
produces hydroxide + H2
X (s) + 2H2O (i) -> X(OH)2 (s) + H2 (g)

# data[].attributes.body
produces oxide + H2
X (s) + H2O (g) -> XO (s) + H2 (g)

# data[].attributes.body
form metal hallides
X (s) + Cl2 (g) -> XCl2 (s)

# data[].attributes.body
forms metal oxide
X (s) + O2 (g) -> XO (s)