Which molecular formula is written incorrectly?

co
ch4
br4si
n2

I believe your answer would be the 3rd one

is written incorrectly

Explanation:

In a molecular formula, the central atom in it's lewis structure is written first followed by other bonded atoms.

The least electronegative atom (except H) is the central atom in a lewis structure.

In , Si is the least electronegative atom as Br has higher electronegativity than Si. Therefore Si is the central atom in lewis structure of . So molecular formula of should be written as .

In all other cases, the least electronegative atom have been written first.

So, is written incorrectly.

they are made of gases.

they have a spherical shape.

they make energy through fusion.

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.