Learn: Atomic Structure

Welcome!Today we'll explore Atomic Structure, a key topic in AQA Chemistry 7405. This will help you understand the composition of atoms and how we study them. Let's dive in!

What is Atomic Structure?Atoms are the building blocks of matter. They consist of three main particles: protons, neutrons, and electrons. Understanding their arrangement helps explain the properties of elements.

Proton Number and Mass NumberThe proton number is the number of protons in an atom, also called the atomic number, and defines the element. The mass number is the total number of protons and neutrons.

What are Isotopes?Isotopes are atoms of the same element with the same proton number but different numbers of neutrons. This gives them different mass numbers but similar chemical properties.

TOF Mass SpectrometryTOF mass spectrometry (time-of-flight) is a method to determine the relative atomic or molecular mass of substances. It works by ionising particles, accelerating them, and measuring their flight time.

Steps in TOF Mass Spectrometry1. Ionisation: Particles are ionised to form positive ions.2. Acceleration: Ions are accelerated by an electric field.3. Drift: Ions travel through a flight tube.4. Detection: Ions hit a detector, generating a signal based on their mass-to-charge ratio.

Interpreting Mass SpectraMass spectra show the abundance of ions against their mass-to-charge ratio (m/z). The peak height represents the relative abundance, while the position shows the m/z value.

Review Time!Great work! You've explored atomic structure, isotopes, and TOF mass spectrometry. Let's test your understanding with a few questions.