Is there any other number in the periodic table thats the same as silicon?

Apulley with a mechanical advantage of 5 will require you to pull times the amount of rope. a. 1/5 b. 5 c. 10 d. 15

Gasoline comes from petroleum, which is made from ancient living things. petroleum, therefore, contains a type of energy. a. heat b. nuclear c. biological d. chemical potential

On a day when the barometer reads 75.23 cm, a reaction vessel holds 250 ml of ideal gas at 20 celsius. an oil manometer ( ρ= 810 kg/m^3) reads the pressure in the vessel to be 41 cm of oil and below atmospheric pressure. what volume will the gas occupy under s.t.p.?