Answer:
SiO2
Explanation:
'Si' is the label given to silicon on the periodic table.
C2H2 is the right answer I believe
I think it’s C but I’m not sure
Answer:
2 and 4
Explanation:
The rest of the changes are chemical. 1 has a chemical reaction happen which makes light sticks glow. 3 is because browning the meat actually causes some new compounds to form and cause caramelization.
For 2, the oxygen is simply heating up and expanding which pops the balloon. 4 is just a phase change of water vapor to liquid water.