Summary
Summary Unit 3.1.1 - Atomic structure NOTES
A-level Chemistry AQA atomic structure notes can apply to most exam boards new spec
[Show more]
Connected book
Book Title:
Author(s):
- Edition:
- ISBN:
- Edition:
Seller
Follow
Content preview
Topic 1: Atomic StructureFundemental particles
g
Mass number and isotopes
Mass number (A) and atomic (proton) number (Z).
Isotopes are atoms of the same element with different numbers of neutrons and the
same number of protons.
Formulas
Proton number = number of electrons
Mass number (Mr) - Atomic number (protons) = neutrons
If an atom has a ‘+’ charge, then the atom has lost an electron. If it has a ‘-’ charge then
the atom has gained an electron.
, Time of flight Mass Spectrometer
The mass spectrometer gives accurate information about relative isotopic mass and also
about the relative abundance of isotopes.
Mass spectrometry can be used to identify elements. Mass spectrometry can be used to
determine relative molecular mass.
Particles of a substance are ionised to form 1+ ions.
Stage 1: Ionisation
Electron impact is when the sample is vapourised and high energy electrons are fired at
it. They are fired from an electron gun which is a hot wire filament with a current that
emits electrons. This knocks off one electron from each particle, forming a +1 ion. This is
used for substances with low formula mass. Fragmentation can occur.
Electrospray ionisation is when the sample is dissolved in a volatile solvent (vapourises at
room temp) and injected through a fine hypodermic needle to give a fine mist. The tip of
the needle is attached to a positive terminal of a high voltage supply. The particles gain a
proton (H+ ion) from the solvent as they leave the needle. Used for biological molecules
with high molecular mass. Fragmentation is rare.
In both methods they exit through a negatively charged plate which attracts the positive
ions
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller anjubellam. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £2.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
79789 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now