The numbers of subatomic particles present in four species W, X, Y and Z are given in the table.
| Species | Number of protons | Number of neutrons | Number of electrons |
| W | 19 | 20 | 18 |
| X | 19 | 20 | 19 |
| Y | 20 | 20 | 18 |
| Z | 20 | 22 | 20 |
Which of these species are isotopic?
W and X
W and Y
X and Z
Y and Z
Did this page help you?
Iodine exists as one isotope with mass number 127.
Chlorine exists as two isotopes with mass numbers 35 and 37.
How many molecular ion (ICl3+) peaks are there in the mass spectrum of ICl3?
2
3
4
5
Did this page help you?
The diagram shows a mass spectrometer.
the sample is vaporised using a heater
electrons are removed from molecules or atoms and positive ions are formed
electrons are added to the molecules or atoms and negative ions are formed
ions are accelerated by an electric field
ions with a greater mass have a smaller deflection
ions with a greater mass have a greater deflection
ions with a greater charge have a smaller deflection
ions are speeded up by a magnetic field
Did this page help you?
1 markThe mass spectrum of a sample of an element has only two peaks.
What is the approximate relative atomic mass of the element in this sample?
191.5
192.0
192.5
193.0
Did this page help you?