Chapter 2 (atoms ions and compounds)
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What are the important polyatomic ions ?
How is the Mr of an element attained from the Mass spectrometer ?
• the percentage abundance of the isotopes in an element can be found by the use of a mass spectrometer Steps: • the sample is vaporised • the sample is ionised to form positive ions • the ions are accelerated - heavy ions move slower • the ions are detected as a mass-to-charge ratio - each ion produces a signal, so the larger the signal the greater the abundance
What is the difference between relative formula and molecular mass ?
• Relative molecular mass is applied to chemicals that have a fixed formula in terms of the number of atoms involved e.g C2H5OH • relative formula mass is applied to chemicals that use an empirical formula to represent them, e.g CaCl2