[blokeybloke]

Hey guys I’m new to chemistry,

I was wondering if someone could explain to me in simple terms what elements, compounds and substances are and explain their differences to me!

Thanks a lot!

[Borek]

You have to show you efforts before receiving help, this is a forum policy.

Definitions are quite easy to locate, have you tried to google them and read them? What have you learned?

[blokeybloke]

You have to show you efforts before receiving help, this is a forum policy.

Definitions are quite easy to locate, have you tried to google them and read them? What have you learned?

Sorry I have looked them up but I am having trouble understanding them. Thanks!

[Borek]

And what do these definitions say? Can you post them? Can you explain what you don't understand?

[blokeybloke]

And what do these definitions say? Can you post them? Can you explain what you don't understand?

Elements are defined as species of atoms as well as substances that are made of one type of atom so I do not know which definition is correct. Also, what exactly are substances and how exactly do we refer to things as "substances" in the context of chemistry? Thanks!

[Borek]

Elements are defined as species of atoms as well as substances that are made of one type of atom so I do not know which definition is correct.

These definitions are not contradicting each other, in a way they say the same thing. Stick to the one you feel more comfortable with.

Substance is not something precisely defined, which is often a source of problems. Typically we mean something like "collection of identical atoms or molecules" or "a form of matter that has constant chemical composition and characteristic properties". This "identical" or "constant" part is important, as substance is just one "thing", as opposed to mixture, which is typically made of several "things". So you can have a substance made of molecules (like pure water) or substance made of identical atoms (like carbon, or iron) - the latter will be referred to as "an element".

Just note what we call an "iron nail" - is not really made of pure iron. It contains also other substances, so it is actually a mixture. That's another possible source of confusion, as the same word will mean something a bit different when used in common situation and when used in chemistry.

[blokeybloke]

Elements are defined as species of atoms as well as substances that are made of one type of atom so I do not know which definition is correct.

These definitions are not contradicting each other, in a way they say the same thing. Stick to the one you feel more comfortable with.

Substance is not something precisely defined, which is often a source of problems. Typically we mean something like "collection of identical atoms or molecules" or "a form of matter that has constant chemical composition and characteristic properties". This "identical" or "constant" part is important, as substance is just one "thing", as opposed to mixture, which is typically made of several "things". So you can have a substance made of molecules (like pure water) or substance made of identical atoms (like carbon, or iron) - the latter will be referred to as "an element".

Just note what we call an "iron nail" - is not really made of pure iron. It contains also other substances, so it is actually a mixture. That's another possible source of confusion, as the same word will mean something a bit different when used in common situation and when used in chemistry.

Hey so when you say “collection of atoms or molecules” do you mean like a physical collection of atoms or molecules? Or do you mean that substances are more like categories that group certain atoms and molecules?

[Borek]

I mean physical collection, like something stored in a jar.

As I wrote, some of these terms are not precisely defined, plus nature doesn't care about our classification attempts and throws at us things that don't fit any definitions we can make - so in the end there are always border cases where things are difficult to classify. But you won't be making huge mistake by sticking to simplified meanings/ideas at the beginning, just remember they are simplified and don't make a mistake of treating them as final/exact. Once things start to click you will see that the reality is more often continuous than discrete (unless we are talking about quantum chemistry ).

[blokeybloke]

I mean physical collection, like something stored in a jar.

As I wrote, some of these terms are not precisely defined, plus nature doesn't care about our classification attempts and throws at us things that don't fit any definitions we can make - so in the end there are always border cases where things are difficult to classify. But you won't be making huge mistake by sticking to simplified meanings/ideas at the beginning, just remember they are simplified and don't make a mistake of treating them as final/exact. Once things start to click you will see that the reality is more often continuous than discrete (unless we are talking about quantum chemistry ).

Hi Borek but doesn’t that mean that the two definitions of an element are contradictory? Because one describes a species or type of atom whereas the other suggests that they are “collections” of atoms.

[Borek]

I think I see your point.

Imagine having a large container of marbles. You have marbles of different colors - red ones, yellow ones, blue ones and so on. Let's call all the red marbles "marbles of carbon". You can take a single marble and say "it is a marble of carbon", or "it is carbon", you can gather a jar of red marbles and say "it is carbon", "I have a jar of carbon", "I have a jar of carbon marbles". Same with atoms and carbon is an element.

[blokeybloke]

Elements are defined as species of atoms as well as substances that are made of one type of atom so I do not know which definition is correct.

Substance is not something precisely defined, which is often a source of problems. Typically we mean something like "collection of identical atoms or molecules" or "a form of matter that has constant chemical composition and characteristic properties". This "identical" or "constant" part is important, as substance is just one "thing", as opposed to mixture, which is typically made of several "things". So you can have a substance made of molecules (like pure water) or substance made of identical atoms (like carbon, or iron) - the latter will be referred to as "an element.

Hi again Borek, so going back to the idea of “substances”. If I were to say it that two substances are reacting with each other, would that then mean that a certain collection of atoms/molecules are interacting with ANOTHER collection of atoms/molecules?

[Borek]

Hi again Borek, so going back to the idea of “substances”. If I were to say it that two substances are reacting with each other, would that then mean that a certain collection of atoms/molecules are interacting with ANOTHER collection of atoms/molecules?

Yes.