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Difference between atoms, molecules and element?

gfhfghd

Also, is O2 (oxygen) 1 molecule consisting of 2 atoms?
I'm a bit confused.

Reply 1

gfhfghd

Also, 2Mg means 2 atoms of the magnesium molecule?

Reply 2

Jacko1222

An atom is a single nucleus, made up of protons and neutrons, with orbiting electrons.
A molecule is a ‘group’ of atoms chemically bonded together to create a new substance with different properties.
An element is a type of atom/substance made up of a single type of atom (for example, Carbon-12 is an element where all of the atoms have 6 protons, 6 neutrons and 6 electrons).

Original post by gfhfghd

Also, is O2 (oxygen) 1 molecule consisting of 2 atoms?
I'm a bit confused.

Yes! O2 is two oxygen atoms bonded together

Original post by gfhfghd

Also, 2Mg means 2 atoms of the magnesium molecule?

2Mg is two magnesium atoms which are not bonded together.

Reply 3

TheMythicalBeast

A molecule is made up of two or more atoms, an element is an atom with a specific number of protons and an atom is the smallest particle of an element that exists. An atom is singular, atoms make up molecules, each atom can be identified as a specific element depending on how many protons it has

Reply 4

Anonymouspsych

Original post by gfhfghd

Also, 2Mg means 2 atoms of the magnesium molecule?

Be careful, magnesium isn't a molecule. But yes 2Mg means 2 magnesium atoms.

Reply 5

TheMythicalBeast

Original post by Jacko1222

2Mg is two magnesium atoms which are not bonded together.

Just to add on that, in case someone didn’t catch on, 2Mg are two magnesium atoms, but they are not a molecule or two molecules as the atoms are not bonded together as mentioned above

Reply 6

gfhfghd

Original post by TheMythicalBeast

Just to add on that, in case someone didn’t catch on, 2Mg are two magnesium atoms, but they are not a molecule or two molecules as the atoms are not bonded together as mentioned above

How do you know that in the oxygen molecule the 2 atoms are bonded together and in the 2Mg the 2 atoms are not bonded together and that it's an element?
Is it because for oxygen the 2 comes after the O (O2) and for Magnesium the 2 comes before the Mg (2Mg)

Reply 7

gfhfghd

Original post by Jacko1222

Reply 8

Vikingninja

Original post by gfhfghd

Number in front means the number of molecules and separate elements. Number after in subscript represents number in a molecule. 2H2O means that there are 2 H2O molecules where there are 2 H elements and 1 O.

Reply 9

BTAnonymous

Original post by gfhfghd

Yes, the 'bigger' numbers indicate quantity of molecules. For example:

Mg + O(small 2) --> MgO

We need 2 oxygens to balance the RHS

Mg + O(small 2) --> 2MgO

But now we need 2 molecules of magnesium on the LHS

2Mg + O(small 2) --> 2MgO

The 'small' number indicates how many atoms of that element make up that molecule. Eg, H(small 2)SO(small 4) indicates there are 2 hydrogens and 4 oxygens in sulfuric acid.

Reply 10

gfhfghd

OK so,
F2 (small 2) means 2 fluorine atoms in the fluorine molecule?
CaCl2 is 1 calcium element and 2 chlorine atoms?
MgSO4 is one magnesium element and 1 sulfur element and 4 oxygen atoms?

Reply 11

gfhfghd

Original post by BTAnonymous

OK so,
F2 (small 2) means 2 fluorine atoms in the fluorine molecule?
CaCl2 is 1 calcium element and 2 chlorine atoms?
MgSO4 is one magnesium element and 1 sulfur element and 4 oxygen atoms?

Reply 12

BTAnonymous

Original post by gfhfghd

OK so,
F2 (small 2) means 2 fluorine atoms in the fluorine molecule?
CaCl2 is 1 calcium element and 2 chlorine atoms?
MgSO4 is one magnesium element and 1 sulfur element and 4 oxygen atoms?

Precisely.

If you had 2CaCl(small 2) however then it's 2 times everything!

So 2 calcium atoms and 4 chlorine atoms.

This means you have 2 CaCl2 molecules however, it does not mean there 2 calcium atoms and 4 chlorine atoms bonded together.

Reply 13

gfhfghd

Original post by BTAnonymous

So as you said the bigger number indicate quantity of molecule. And will elements there will not be a number in front or after? Eg. O (oxygen) is an element. and O2 is 2 oxygen atoms in the molecule (because 2 atoms of the same element are bonded together?)

(edited 6 years ago)

Reply 14

BTAnonymous

Original post by gfhfghd

what do you mean?

Oxygen is an element, however, as a gas, it never exists as O by itself because that is less stable. Instead,it exists as 2 oxygen atoms, O2; an oxygen molecule.

Reply 15

gfhfghd

Original post by BTAnonymous

what do you mean?

Oxygen is an element, however, as a gas, it never exists as O by itself because that is less stable. Instead,it exists as 2 oxygen atoms, O2; an oxygen molecule.