What is this balanced?
Al2O3---> Al+O2

The balanced equation :

2Al₂O₃⇒ 4Al+3O₂

Given

Reaction

Al₂O₃⇒ Al+O₂

Required

Balanced equation

Solution

A chemical reaction is said to be balanced if the number of elements involved in the reaction is the same (either the reactants or the products)

The reaction above is said to be unbalanced because the number of elements Al and O in the reactants and products is not the same.

The balancing step

1. Give a coefficient

Al₂O₃⇒ aAl+bO₂

2. Make an equation

Al, left = 2, right = a⇒a=2

O, left = 3, right = 2b⇒2b=3⇒b=3/2

The equation becomes :

Al₂O₃⇒ 2Al+3/2O₂ x2

2Al₂O₃⇒ 4Al+3O₂

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.