What is the difference between a mechanical wave and an electromagnetic wave?
O
A mechanical wave travels through empty space, while an electromagnetic wave travels through matter.
O A mechanical wave has a short wavelength, while all electromagnetic waves have long wavelengths.
O A mechanical wave has a high frequency, while all electromagnetic waves have low frequencies.
O Amechanical wave travels through matter, while an electromagnetic wave travels through empty space.

D

Explanation:

Mechanical waves need a mater interference to be able to travel. Electromagnetic waves are able to travel through empty space or in a vacuum.

  the grams     of oxygen gas   that can be produced     is 20.6   grams of o₂

calculation

2liclo₃ →   2 licl + 3 o₂

step 1:   find the moles of liclo₃

moles = mass÷ molar mass

from periodic table the molar mass of liclo₃ =6.9 +35.5   +(16 x3) =90.4 g/mol

moles=38.7 g÷90.4 g/mol=0.4281   moles

step 2:   use the   mole ratio   to calculate the moles of o2

from equation above, liclo₃: o₂   is 2: 3  

therefore the moles of   o₂=0.4281 moles x3/2 =0.6422   moles

step 3: find mass   of o₂

mass= moles x molar mass

from periodic table the   molar mass of   o₂ = 16 x2= 32 g/mol

mass=0.6422   moles   x   32 g/mol = 20.6 grams of o₂