Define spectator ions.​

Explanation:

Spectator ions may be either cations (positively-charged ions) or anions (negatively-charged ions). The ion is unchanged on both sides of a chemical equation and does not affect equilibrium. When writing a net ionic equation, spectator ions found in the original equation are ignored. Thus, the total ionic reaction is different from the net chemical reaction.

(source thought co)

tracks, burrows, eggshells, nests, tooth marks, or gastroliths

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer