1 / 10

Understanding Atomic Structure & Isotopes: Key Concepts and Applications

Discover how atoms differ in atomic structure, isotopes, and mass, and learn to find atomic mass and identify isotopes using average atomic mass. Explore practical applications and exceptions in isotopic composition.

maisie-church
Download Presentation

Understanding Atomic Structure & Isotopes: Key Concepts and Applications

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. How atoms differ L

  2. Atomic Number • Moseley discovered that each element had a unique charge (+) in its nucleus • Number of p+ Atomic Number = # of p+ = # of e-

  3. Isotopes • All atoms of an element have the same number of: • p+ • e- • Number of n0 changes • Isotopes – the same element with a different number of n0 but the same number of p+ and e- • Thus, they have a different mass

  4. Mass number • To identify isotopes • Number after element’s name • Ex: • Carbon-14 • Potassium-39 • Short hand: • 3919K • 146C • Top number is sum of n0 and p+ • Bottom number is the atomic number

  5. Finding the number of n0 n0 = mass # - atomic #

  6. Mass of individual atoms • p+ = 1.67 x10-24g • n0 = 1.67 x10-24g • e- = 1/1840th of 1.67 x10-24g • So small scientist came up with Atomic mass units (amu) • Gave c-12 an exact mass of 12.0000 • 1 amu = 1/12th the mass of C-12

  7. Practice

  8. Atomic mass • Weighted average of the isotopes of that element Average atomic mass = (isotope mass1 x %1) + (isotope mass2 x %2) + (isotope mass3 x %3)…. • Cl • 75% Cl-35 • 25% Cl-37 • (35 x 0.75) + (37 x 0.25) = 35.5 26.25 + 9.25

  9. Hydrogen • H-1 Abundance 99.9851% • H-2 Abundance 0.0151% • Helium • He-3 abundance 0.0001373% • He-4 abundance 99.9998633%

  10. Application of average atomic mass • The closer an element is to a whole number for its average atomic mass the more likely it is that it’s most abundant isotope has that atomic mass • Ex: F has an atomic mass of 18.998amu • F-19 (99%) • There are exceptions • Br has an atomic mass of 79.904amu • Br-79 (51%) & Br-81 (49%) • Br-80 doesn’t exist

More Related