They are good conductors of heat and electricity.
They are solid at room tempature
They have a high melting point
Rubidium or strontium have larger a larger atomic radius since the further left on the periodic table you go, the larger the sizes of the atoms are. This trend can be explained through effective nuclear charge which explains how the further left and down you go, the less the atoms nucleus is able to pull in the electrons around it.<span />
Though she hits the drum, the papers on the drum also vibrate.
This is due to the fact that when she hits the drum, the shock waves created by the hitting travel through the skin of the drum and radiate outwards. When they encounter the papers, some of this energy is transmitted to the papers and the papers also vibrate.