Obsidian is volcanic silicon dioxide glass that forms naturally when lava cools quickly. Because the lava cools so quickly, crystals do not have time to form. Which evidence explains why obsidian is not classified as a mineral?

D.na is the answer hope this

the catch is that the top numbers are atomic masses the bottom numbers are the numbers of protons and electrons in an uncharged atom. they are the number of that atoms as you would find them on the periodic table. further, the numbers on the left are used to determine the missing numbers on the right

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

Neither model is able to show the reactivity of potassium.

  super sorry but i dont know lo