Question

which element is oxidized and which is reduced in the following reaction 2na+cl2=2nacl

Answer 1

2Na + Cl2 → 2NaCl

Actually , Here reaction is completing in two process . e.g oxidation reaction , and reduction reaction.

we know,
all metals oxidise , becoz metals have tendency to loss electrons .
we know ,
definition of oxidation :- lossing of electrons is known as oxidation .
e.g
Na → Na^+ + e ------------(1)
so, here, Na get oxidised .

we also know ,
all non- metals reduced becoz , non- metals have tendency to accept electrons .

here ,
Cl2 +2e →2Cl^- -------(2)
reduction :- accepting of electrons .
so, Here , Chlorine get reduced .

Answer 2

Oxidation is addition of Oxygen and removal of Hydrogen.

Reduction is removal of Oxygen and addition of Hydrogen

So considering the given reaction i.e. 2na+cl2=2nacl

I would say that "Sodium" is oxidized and "Calcium" is reduced.

It is so because - before reaction Na = +0 and Cl = +0

But after reaction Na becomes + and Cl becomes -

So it is clear that "Sodium" is oxidized and "Calcium" is reduced.