I believe the answer is: in order not to write very big or very small number values
Mg (s) + HCl (aq) → MgCl₂(s) + H₂(g)
Looking at the equation :
We have 1 Mg at the left hand side and 1 Mg as well on the right hand side.
So that is balanced.
We have 1 H at the left hand side and 2 H on the right hand side.
So that is not balanced. Same for Chlorine. Cl.
We add 2 to the HCl on the left hand side and that balances it.
Mg(s) + 2HCl(aq) → MgCl₂(s) + H₂(g)
Answer:
Au
Explanation:
For the density of a face-centered cubic:
where
= molar mass of the compound
avogadro's constant
the volume of a unit cell
Given that:
Density 
= 19.30 g/cm³
a = 0.408 nm
a = 
a = 
∴
Thus, the molar mass of 197.37 g/mol element is Gold (Au).
Answer:
6 different frequencies
Explanation:
From energy level 1 to 2 is one frequency, from energy level 1 to 3 is one frequency and From energy level 1 to 4 is one frequency. So, we have a total of 3 frequencies for transition from energy level 1.
From energy level 2 to 3 is one frequency and from energy level 2 to 4 is one frequency. So, we have a total of 2 frequencies for transition from energy level 2.
From energy level 3 to 4 is one frequency.
So we have a total of 3 + 2 + 1 different frequencies = 6 different frequencies.
Note that the reverse process for each step produces the same frequency as the step in consideration.
