This is a metallic bond.
I hope this helps.
Condensation because condensation is a process of freezing
The reaction would produce bubbles of gas.
We can prepare 3-5 test tubes of acid with increasing concentrations. Then, we add antacid tablets to each and note the time taken for the tablet to dissolve and stop producing bubbles. The lesser the time taken, the greater the rate of reaction.
Atomic mass silicon = 28.085 u
1 mol Si ---------------- 28.085 g
? ------------------------ 245 g
245 x 1 / 28.085 => 8.72 mol
answer A