Explain why the first ionisation energies decrease down the group.
Explain why, for each element, there is a large increase between the 2nd and 3rd ionisation energies.
Write out the full electronic configuration of strontium. $1s^2\ 2s^2\ 2p^6$ ........................................................
Explain why the mass spectrum of strontium contains four different peaks.
Calculate the atomic mass, $A_r$, of this sample of strontium. Give your answer correct to three significant figures.
Explain, in terms of electron transfer, what the term oxidising agent means.
The percentage composition by mass of $A$ is: Ba, $45.1$; Cl, $23.4$; O, $31.5$. Calculate the empirical formula of $A$.
Give the formulae for the compounds $X$, $Y$ and $Z$.
Name the reagent required to change $Y(s)$ into $Z(aq)$ for reaction $1$, and write an equation for the reaction.
How would you convert a sample of $Z(s)$ into $Y(s)$ in reaction $2$?
Give equations for converting Mg into $X$, and $Z(s)$ into $Y$. Mg to $X$ $Z$ to $Y$