Question

Which of the following represents a compound? H2O, O2, C20, or H2?

Answer 1

do you know the difference between a molecule and a compound?

Answer 2

Not sure...

Answer 3

we'll a molecule is a specific unit of atoms covalently bound to one another.

Out of the ones you posted, water, oxygen gas and hydrogen gas are all molecules.

A compound is a bit harder to define, because it can be a molecule as well as ionic solids.

Answer 4

So, you believe non of the above are compounds, because H2o (water), O2 (oxygen), C2o (gas), and H2 (hydrogen) are all molecules?

Answer 5

we'll i think \(C_{20}\) is compound because it's a pure substance AND because it doesn't have a defined structure.

Answer 6

Okay, thank you! I will check in with my teacher and let you know.

Answer 7

okay, good luck!

Answer 8

I actually have another question-
Air contains mostly nitrogen (78%) and oxygen (21%), It also contains other gases, including carbon dioxide and helium, and various pollutants (both gases and solids). I want to know why air is a mixture, whether it is homogeneous or heterogeneous, and how it may be separated into it's components.

Answer 9

I believe it is heterogeneous because the components of air are unevenly distributed.

Answer 10

why do you propose that it's not distributed evenly?

Answer 11

Because nitrogen is 78% and oxygen is 21%

Answer 12

Are those not it's components?

Answer 13

yeah but it's evenly distributed. It's like there's patches of nitrogen and no oxygen present.

Answer 14

it's not like***

Answer 15

Oh, okay. So how can it be separated into it's components?

Answer 16

so it is a homogenous mixture, just to be clear.

Um you can cool the mixture in a controlled fashion and since the components have different boiling points they'll condense at different temperatures.

Answer 17

I actually need to answer why air is a mixture. Not how I know

Answer 18

Is air a mixture because it has several components?

Answer 19

yes, and it's homogeneous because the components are uniformly distributed.

Answer 20

Okay. Thank you!

Answer 21

you're welcome

Answer 22

apparently (news to me), a compound is made from more than 2 elements, so the answer would've been water.

Answer 23

It is okay :) I did get the answer wrong but it is fine. Now I know for next time :)