Fill in the table to show the composition and identity of some atoms and ions.
Protons, neutrons and electrons travel in different ways in an electric field because their properties are not the same. The diagram shows the route of a beam of electrons in an electric field. Add and label lines to show the paths of beams of protons and neutrons in the same field.
The fifth to eighth ionisation energies of three elements in the third period of the Periodic Table are given. The symbols used for reference are not the actual symbols of the elements.
State and explain the group number of element Y.
State and explain the overall trend in first ionisation energies across the third period.
Explain why the first ionisation energy of element Y is lower than that of element X.
Complete the electronic configuration of element Z: $1s^2$ ____________________ .
A strontium sample is a blend of four isotopes. Details for three of these isotopes are shown in the table.
Calculate the abundance of the fourth isotope.
The relative atomic mass of this strontium sample is $87.71$. Calculate the mass number of the fourth isotope.