Flourine
Chlorine
Bromine
Iodine
Astatine
Explanation:
Molecular mass of sugar =
: = 432 g/mol
Atomic mass of carbon atom = 12 g/mol
Atomic mass of hydrogen atom = 1 g/mol
Atomic mass of oxygen atom = 16 g/mol
a) Percentage of an element in a compound:

Percentage of carbon by weight in
:

Percentage of hydrogen by weight in
:

Percentage of oxygen by weight in
:

b) Percentage of mole each of the elements present in sugar:
=
In mole of sugar we have 12 moles of carbon atom , 22 moles of hydrogen atoms and 11 moles of oxygen atoms.
Percentage of carbon by mole in
:

Percentage of hydrogen by mole in
:

Percentage of oxygen by mole in
:

When magnesium is burned, it reacts with oxygen in air not with the fire. The fire is the energy needed for the reaction to happen. Magnesium reacts with oxygen forming magnesium oxide. The light emitted from the reaction is because the reaction produced a lot of heat.
Answer:
The wavelength of the line in the emission line spectrum of hydrogen caused by the transition of the electron for the given energy levels is 
Explanation:
Given :
The energy E of the electron in a hydrogen atom can be calculated from the Bohr formula:

= Rydberg energy
n = principal quantum number of the orbital
Energy of 11th orbit = 

Energy of 10th orbit = 

Energy difference between both the levels will corresponds to the energy of the wavelength of the line which can be calculated by using Planck's equation.


(Planck's' equation)


The wavelength of the line in the emission line spectrum of hydrogen caused by the transition of the electron for the given energy levels is 