It applies to both physical and chemical changes.
Answer:
E = hf
E = hc/lamda
where E-energy,
h-planck's constant (6.62 x 10^-34 Js)
f- frequency ( f = c/lamda)
c-velocity of light ( 3 x 10^8 m/s)
lamda- wavelength
you can this formula to solve all the 4 questions.
Answer:
The number of mole represented is 2.07 moles
Explanation:
Using the formula
n = m/Mm
n - mole
m - mass
Mm- molar mass
Since the mass is given to be 213g
So lets calculate the molar mass of sodium bromide (NaBr)
The molar mass of Na = 22.99
Br = 79.904
Molar mass = 22.99+79.904
= 102.894g/mol
Using the formula n = m/Mm
n = 213g/ 102.894g/mol
n = 2.07moles
