Learn: Atomic Structure

Welcome!Today, we'll explore Atomic Structure, a key topic in AQA Chemistry 7405. We'll break it down step by step so you feel confident in understanding the basics and applications.

What is Atomic Structure?Atomic Structure refers to the arrangement of subatomic particles (protons, neutrons, and electrons) in an atom. Understanding this helps explain chemical properties and reactions.

Atomic Number and Mass NumberThe atomic number is the number of protons in an atom, which defines the element. The mass number is the total number of protons and neutrons. For example, carbon has an atomic number of 6 and a mass number of 12.

IsotopesIsotopes are atoms of the same element with different numbers of neutrons but the same number of protons. For example, carbon-12 and carbon-14 are isotopes of carbon.

What is TOF Mass Spectrometry?TOF mass spectrometry (Time of Flight) is a technique used to measure the mass-to-charge ratio of ions. It helps identify isotopes and determine molecular structures.

How Does TOF Mass Spectrometry Work?1. The sample is ionised to form charged particles.2. The ions are accelerated in an electric field.3. The ions travel through a tube, with lighter ions reaching the detector first due to higher speeds.

Interpreting Mass SpectraMass spectra show peaks representing isotopes and their relative abundances. The x-axis shows the mass-to-charge ratio, and the y-axis shows the intensity.

Review Time!Great work! You've learned about atomic number, mass number, isotopes, TOF mass spectrometry, and mass spectra interpretation. Let's test your understanding with a few questions.