Lambda = h\ Mv
lambda = 6.624 x 10^-34 / 9.1 x 10^-31 x 2.5 x 10^7
lambda = 2.9 x 10^-11 is your wavelength
Heat required : 4.8 kJ
<h3>Further explanation
</h3>
The heat to change the phase can be formulated :
Q = mLf (melting/freezing)
Q = mLv (vaporization/condensation)
Lf=latent heat of fusion
Lv=latent heat of vaporization
The heat needed to raise the temperature
Q = m . c . Δt
1. heat to raise temperature from -20 °C to 0 °C

2. phase change(ice to water)

3. heat to raise temperature from 0 °C to 25 °C


Answer:
S + 4 Cl2
Explanation:
Sulphur - S
1 mol of Sulphur = S
Chlorine = Cl2
4 moles of Chlorine = 4Cl2
4S + 2Cl2
Incorrect option
S + 4 Cl2
Correct option
S + 2Cl2
Incorrect option
S + Cl2
Incorrect option
The only list containing molecules is list #4
NaCl, N2, and H2O are all made up of more than one element, making them molecules. The other lists contain an element. Mg, He, and Fe are elements, not molecules.
Hope this helps!