Based on your observations from the Can Crush Lab, why would a helium balloon that rises into the atmosphere eventually burst? Atmospheric pressure outside the balloon increases as the balloon rises.
Atmospheric pressure outside the balloon decreases as the balloon rises.
Helium molecules inside the balloon decrease as the balloon rises.
Helium molecules inside the balloon increase as the balloon rises.

Outside of the balloon, air increasing pressure even as balloon grows.

Explanation:

The volume of the air increased with increase in ambient height, meaning that the amount of air molecules per unit area decreases. The pressure placed by the air is therefore decreased due to this decrease in air density.

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