Question

mixture or pure substance: 1.water 2.blood 3.the oceans 4.iron 5.brass 6.uranium 7.wine 8.leather 9.table salt (NaCl)

Answer 1

Do you know the difference between a mixture and a pure substance?

Answer 2

kind of, well these are the ones I think are right:
3.mixture
4.pure substance
5.mixture
6.pure substance
7.mixture

Answer 3

the salt, for instance, confuses me because even though it's two elements combined its also one thing. so im just confused over the whole thing

Answer 4

In sodium chloride, there are 2 elements, but together they're 1 molecule.
A mixture is when there are 2 or more different molecules present.
A pure substance consists only of 1 atom or molecule.

So NaCl is a pure substance, but when you dissolve salt in water, you'll get a mixture because now there are 2 kinds of molecules, NaCl and H2O.

Answer 5

thank you! that answered a lot of my questions! what about brass, blood, leather? they are the only ones im not completely sure about

Answer 6

Brass is an alloy.
It contains zinc and copper.
So that would make it a mixture :)
Every alloy is a mixture.

Does blood contain 1 kind of atom/molecule? or more
And how about leather.

Answer 7

im pretty positive that blood is a mixture and has a lot of atoms and molecules (but i'm not sure)
and since leather is a combination of a bunch of stuff im guessing its a mixture? :)

Answer 8

correct and correct :)

Answer 9

one last thing. how do you know sodium chloride only has one molecule? and are all metals then mixtures? (besides the elements)

Answer 10

Sodium cloride is NaCl. NaCl is 1 molecule so it's a pure substance since sodium and chlorine are bonded together.
Metals are all pure substances, and then i'm talking about the metals you find in a periodic table. Like copper, gold, iron, titanium etc.
When there are 2 metals in a substance, you wouldn't call it a metal anymore, it's would be an alloy. In an alloy, metals are not chemically bonded together, only physically.
So steel is an alloy, since it's a mixture of iron with some other element.

Answer 11

thank you for all your help!!

Answer 12

You're most welcome \(\Huge\ddot\smile\)