Year 12s: what will be the first way you research your future options? >>

Simply definition question:

Hey.

I am a Year 13 Physics student and thought that I understood the concept of the atom, an element etc. quite well. However, reading today has realised I do not understand it all fully.

Can a single atom constitute an element?

I know that a collection of atoms with the same number of protons in their nuclei can but not whether this is true for a single atom.

Atoms are often described as being "of an element" and that is partly what led me to ask this question.

Reply 1

shengoc

Original post by Magu1re

Hey.

I am a Year 13 Physics student and thought that I understood the concept of the atom, an element etc. quite well. However, reading today has realised I do not understand it all fully.

Can a single atom constitute an element?
Yes, a particular type of atom constitutes what an element is really. ie atom consists of protons, neutrons and electrons(from chemists perspective), hence a hydrogen atom is different from helium atom and other elements.

I know that a collection of atoms with the same number of protons in their nuclei can but not whether this is true for a single atom.

Atoms are often described as being "of an element" and that is partly what led me to ask this question.

if you have different atoms present as a mixture, ie doping of certain metals, alloys can be formed - these are no longer elements, as they now contains more than one type of atoms.

Reply 2

Magu1re

Original post by shengoc

if you have different atoms present as a mixture, ie doping of certain metals, alloys can be formed - these are no longer elements, as they now contains more than one type of atoms.

Cool. So if I have a single atom with one proton in it's nucleus and one electron orbiting it then this "thing" can be called the element hydrogen?

Reply 3

Plato's Trousers

Original post by Magu1re

Cool. So if I have a single atom with one proton in it's nucleus and one electron orbiting it then this "thing" can be called the element hydrogen?

yes, you can have just one atom of an element, for sure. In the case you describe, you would have one atom of hydrogen. Or you could have a gazillion atoms of hydrogen, or a litre of hydrogen or however much you like (provided you can afford it and you take appropriate fire precautions :biggrin:

)

An atom is the smallest amount of an element you can have, because it is the atom that defines an element's identity (ie the number of protons and electrons in it). Once you start breaking atoms down into their bits, you no longer have an element (you just have the bits - neutrons, electrons, quarks etc)