Can anyone explain to me what does the little “s” means at the end : / . btw it’s an easy question

If equal masses of the listed metals were collected , which would have a greatest volume ? a. aluminum 2.70,b.zinc7.14,c.copper 8.92,d.lead 11.34

Write the balanced equation for a reaction between aqueous nitric acid (hno3) and solid lithium metal (this is a single replacement reaction)

Can someone me with 1 to 4 plz. fast