Answer:
The speed of an electron is 0.01908 m/s.
Explanation:
De-Broglie wavelength is given by:

where,
= wavelength of a particle
h = Planck's constant = 
m = mass of particle
v = velocity of the particle
Velocity of an electron = v
Mass of an electron = 
Wavelength of electron is twice the displacement in seconds which is velocity of an electron.
Then.wavelength of an electron = 

v = 0.01908 m/s
The speed of an electron is 0.01908 m/s.
Answer:
All the carbon will combust with atmospheric oxygen to form carbon dioxide. This means that the charcoal present will become consumed to form colorless carbon dioxide gas.
Explanation:
First we calculate the number of moles of sugar (which I assume is sucrose).
number of moles = mass / molecular weight
number of moles of sugar = 19 / 342 = 0.055 moles
Now we may calculate the molarity of the solution.
molarity = number of moles / solution volume (L)
molarity = 0.055 / 0.05 = 1.1 M
<span>
Magnesium appears as the cation Mg 2+ and Oxygen appears as the anion O 2- and when combined they create MgO, which is Magnesium Oxide.</span>