Which molecule could have an expanded octet? hno2 h2co3 h3po4?

 is the molecule that can have an expanded octet.

Octet Expansion:

It means that the molecule or atom needs more electron than they require in octet rule.

has 32 valence electrons in its outermost shell instead of 8 valance electrons.

Therefore, is the molecule that have expanded octet.

To know more about Octet expansion,

link

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.

i'm pretty sure its b i might be wrong though!