2.1 Atomic Structure and Isotopes

Question 1

What is an isotope

Answer 1

Atoms of the same element with different numbers of neutrons and different masses. Most elements are made up of a mixture of isotopes

Question 2

How are isotopes represented

Answer 2

Mass number (A)
                                Chemical symbol Eg. Au
Atomic number (z)

Question 3

Do isotopes react differently?

Answer 3

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

Question 4

What differences are there between isotopes

Answer 4

Small differences in physical properties
Higher mass isotopes with a higher melting point, boiling point and density
BUT chemical reactions are the same

Question 5

What is heavy water

Answer 5

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

Question 6

What is an ion

Answer 6

A charged atom

The number of electrons is different from the number of protons

Question 7

What is a cation

Answer 7

A positive ion, atoms with fewer electrons than protons, thus have an overall positive charge

Question 8

What is an anion

Answer 8

A negative ion, atoms with more electrons than protons, thus have an overall negative charge

Question 9

Ions are always shown…

Answer 9

…with their overall relative charge

Eg. Mg2+