2.1 Atomic Structure and Isotopes Flashcards
What is an isotope
Atoms of the same element with different numbers of neutrons and different masses. Most elements are made up of a mixture of isotopes
How are isotopes represented
Mass number (A) Chemical symbol Eg. Au Atomic number (z)
Do isotopes react differently?
No. Different isotopes of the same element have the same number of electrons and the number of neutrons has no effect on reactions thus they react similarly
What differences are there between isotopes
Small differences in physical properties
Higher mass isotopes with a higher melting point, boiling point and density
BUT chemical reactions are the same
What is heavy water
Used to control processes in nuclear reactors
H2O molecules nearly all contain the Hydrogen-1 isotope but in heavy water, D2O, all molecules contain the Hydrogen-2 (deuteurium) isotope
D2O has a greater density than H2O, higher melting point and higher boiling point
What is an ion
A charged atom
The number of electrons is different from the number of protons
What is a cation
A positive ion, atoms with fewer electrons than protons, thus have an overall positive charge
What is an anion
A negative ion, atoms with more electrons than protons, thus have an overall negative charge
Ions are always shown…
…with their overall relative charge
Eg. Mg2+