Learn: Atomic Structure

Welcome!Today we'll learn about Atomic Structure. This topic is essential for understanding the building blocks of matter and how we determine the makeup of atoms. Let's dive in!

What is Atomic Structure?Atomic structure refers to the arrangement of subatomic particles in an atom. Atoms are made up of three types of particles: protons, neutrons, and electrons. Protons and neutrons are found in the nucleus, while electrons orbit around the nucleus.

Proton Number and Mass NumberThe proton number (atomic number) is the number of protons in an atom's nucleus. It determines the element's identity. The mass number is the total number of protons and neutrons in the nucleus. For example, carbon has an atomic number of 6 and usually a mass number of 12.

IsotopesIsotopes are atoms of the same element with the same number of protons but different numbers of neutrons. This means their mass numbers differ, but their chemical properties remain similar. For example, carbon-12 and carbon-14 are isotopes of carbon.

Introduction to TOF Mass SpectrometryTime-of-Flight (TOF) Mass Spectrometry is a technique used to determine the mass and relative abundance of ions. It involves ionising atoms or molecules, accelerating them, and measuring the time they take to reach a detector. This helps us identify substances and their isotopes.

Steps in TOF Mass Spectrometry1. Ionisation: Atoms or molecules are ionised, usually by electron impact or electrospray ionisation.2. Acceleration: Ions are accelerated by an electric field so they all have the same kinetic energy.3. Flight: Ions travel through a region with no electric field, and their time of flight is measured.4. Detection: Ions hit a detector, creating a signal proportional to their abundance.

Mass Spectra InterpretationA mass spectrum shows the relative abundance of ions plotted against their mass-to-charge ratio (m/z). The height of each peak represents the abundance of an isotope, while the m/z value indicates the mass of the ion.

Review Time!Great work! You've learned about atomic structure, including key concepts like proton and mass numbers, isotopes, and mass spectrometry. Let's test your understanding with a few questions.