The electromagnetic waves have a frequency of 2 400 000 000 Hz The speed of electromagnetic waves is 300 000 000 m/s Calculate the wavelength of the electromagnetic waves.

wavelength of the electromagnetic waves=0.125 m

Explanation:

The wavelength of an electromagnetic wave is given as

λ = c/f

where λ=wavelength =??

 c= Speed =300 000 000 m/s

f =frequency=2 400 000 000 Hz

Wavelength =Speed /frequency

=300 000 000 m/s / 2 400 000 000 Hz

=300 000 000 m/s / 2 400 000 000 s⁻¹

=0.125 m

  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

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27