Element or compound? Homogeneous or heterogeneous?

Question

I need both for the following.....

Chlorine,

Water,

Soil,

Sugar Water,

Oxygen,

Carbon Dioxide,

Rocky Road Ice cream

Alcohol,

Pure air,

Iron.

If you could explain how to tell the difference in genral that would be great too! Thanks!

Answer 1

ok, an element is something that cannot be separated into 2 different substances.  (if its on the periodic table, it is an element)

a compound is a mixture of two or more substances

homogeneous mixtures, are made up of two or more things and cannot be seperated by physical means.  take Milk for example.. or salt water

as opposed to

heterogeneous mixtures, are made up of two or more substances that can be separated by physical means.  think of iced tea (ice cubes + tea)  or spagetti (noodles + sauce)

Answer 2

Elements are on the periodic table. If it isn't on the periodic table then it isn't an element.Here's a periodic table. http://www.bpc.edu/mathscience/chemistry...

So chlorine is an element because it's on the periodic table. Chlorine is the element with the symbol Cl.

Water is not on the periodic table so it's not an element. Water is the compound with the symbol H2O. A compound has a definite composition, for example, water is always H2O, made up of 2 hydrogen atoms and one oxygen atom. Soil however is not on the periodic table so it's not an element and soil does not have a definite composition so it's not a compound. Soil can contain many different things so it can't be represented by a chemical formula like water can be represented by the formula H2O so soil is a mixture. Soil is a heterogeneous mixture. Heterogeneous simply means you can tell that it is made up of several different things, for example when you look at soil you can clearly see that there's all kinds of different things mixed together in soil so it's heterogeneous.

Now sugar water is not on the periodic table so it's not an element and don't be fooled by the word water, sugar water is not just H2O, it is a mixture because it does not have a definite composition. Like the name says, sugar water is a mixture of sugar and water. The reason it doesn't have a definite composition is because we can pour any amount of sugar we want into the water. When we say water we know that is always H2O, but when we say sugar water how do we know how much sugar and how much water we're talking about? So because sugar water does not have a definite amount of sugar and water it does not have a definite composition and therefore it is a mixture. It is a homogeneous mixture because you can't tell that there's two different things mixed together just by looking at sugar water. It looks just like plain water so we say it's homogeneous.

So to sum things up, elements are the things on the periodic table, compounds are substances made up of two or more elements like H2, H2O, CH4, Li6BeF4ZrF8 (that last one has a lot of elements!). Compounds always have a definite composition meaning they're always made up of the same amount of the same thing like how water is always made up of 2 hydrogens and one oxygen. Mixtures are things that don't have a definite composition meaning they're not always made up of the same amount of the same thing. Homogeneous mixture means it looks the same throughout the whole thing, you can't really tell that there's different things mixed like air is a homogeneous mixture because when you look at air (you can't really see air but that doesn't matter) it looks the same throughout.(Unless your air is contaminated then it might have some different color gases but that's definitely not normal!) Heterogeneous means it looks different throughout the thing, like when you look at rocky road ice-cream you can clearly tell it's not made of just one thing so it's a heterogeneous mixture.

I've answered some of your questions while explaining the difference between elements, compounds and heterogeneous/homogeneous mixtures. Hopefully this will be enough to help you answer the rest of your questions.

EDIT: I just feel like adding that the words homogeneous/heterogeneous have nothing to do with how hard it is to separate something. The person(s) above that stated that homogeneous mixtures can't be separated by physical means is incorrect. In fact it's quite easy to separate homogeneous mixtures by physical means. You can separate salt water or sugar water by simply letting the water evaporate leaving you with just pure salt or sugar. You can separate a homogeneous mixture like air with a balloon. The smaller gases will escape through even the tiniest openings in a balloon and the larger gases will remain trapped in the balloon. There are much better physical means of separating air but I just thought using a balloon as an example would be better because I'm sure if you've ever filled up a balloon with air and left it lying around you noticed that it got smaller after a while. That's the smaller gases escaping.

Answer 3

Hmm, looking at ur list.. I'm not quite sure if you can deem all of them with both classes... but I'll try my best.

First off Element is a classification of a type of atom (which depends on how many protons, neutrons, etc it has). Compound is a combination/grouping of elements/atoms due to electron-pairing,sharing, or transfer.

Homogenous is a mixture which are mixed and can not be taken apart (or atleast EXTREMELY DIFFICULT TO - like you can't really pluck out the salt after mixing it with water right?) Heterogenous is a mixture in which the components are clearly visible and can be easily taken out (like a salad... you can see the different vegetables and easily pluck out the ones you don't want)

Chlorine: Element in terms of the atom itself. Cl2 is a compound (chlorine gas)

Water: Compound, homogeneous

Soil: Compound?? (It's not an element for sure but don't know if you can really identify it as a compound) It's heterogeneous for sure though

Sugar Water: Homogeneous

Oxygen: it's both an element or compound depending on what you're referring to. O is an element by the atom itself, but O2 is a compound; the air we breathe

Carbon Dioxide: Compound.

Rocky Road Ice Cream: Homogeneous

Alcohol: Compound(s)? Well it's definately Homogenous

Pure Air: Homogenous

Iron: Element

Answer 4

Chlorine, element Cl, homogeneous gas

water, compound H2O, homogeneous its just water with its properties

soil, compound, heterogeneous, it contains minerals of pure elements, simple salts (different ones), and silicates

sugar water, compound, heterogeneous, sugar compound and water compound that are each different in properties alone

oxygen, element, homogeneous

carbon dioxide, compound, homogeneous CAN BE HOMOGENEOUS AND CHLORINE TOO IF IN VACUUM, but you may have other gases in that case it is normally heterogeneous but given the way you list it alone go with HOMOGENEOUS

rocky road, compound, heterogeneous with sugars, preservatives, and others

alcohol (in pure form, not in water), compound (different elements), homogeneous

pure air, compound and element (nitrogen, carbon dioxide, oxygen), but compound overall, heterogeneous

iron, element Fe, homogeneous