Answer:
9.12 * 10^20 photons
Explanation:
Given that;
E=n⋅h⋅ν
Where;
E= energy of the electromagnetic radiation
n = number of photons
h = Plank's constant
ν = frequency of electromagnetic radiation
Hence;
n = E/hν
n = 3.46 × 10 -19/6.6 * 10^-34 * 575 * 10^-9
n = 3.46 × 10 -19/3795 * 10^-43
n= 9.12 * 10^20 photons
Answer:
A- beryllium
B- calcium
C- magnesium
Explanation
NOTE: all element in group 2 have 2 balance electrons
First let’s start with B- number of electrons= number of protons which is equal to the atomic number. therefore, the answer is calcium as it’s atomic number is 20
C- magnesium will have three energy levels considering it has 12 electrons (2,8,2).
A- beryllium is the lightest one in group 2 as it has the atomic mass of 9.0122.
Answer:
What do you mean need more details
Explanation:
