Electrons: negative
Protons: positive
Neutrons: nuetral
Answer : The chemical symbol for this element is, (La)
Explanation : Given,
Mass of 
= 0.760 g
Mass of 
= 1.610 g
The given chemical reaction is:
First we have to calculate the moles of and .
Molar mass of Cl = 35.5 g/mole
Let the molar mass of element 'X' be, M
![\text{Moles of }XCl_3=\frac{0.760}{[M+3(35.5)]}](https://tex.z-dn.net/?f=%5Ctext%7BMoles%20of%20%7DXCl_3%3D%5Cfrac%7B0.760%7D%7B%5BM%2B3%2835.5%29%5D%7D)
and,
Molar mass of I = 126.9 g/mole
Let the molar mass of element 'X' be, M
![\text{Moles of }XI_3=\frac{1.610}{[M+3(126.9)]}](https://tex.z-dn.net/?f=%5Ctext%7BMoles%20of%20%7DXI_3%3D%5Cfrac%7B1.610%7D%7B%5BM%2B3%28126.9%29%5D%7D)
From the balanced chemical reaction we conclude that,
The moles of ratio of and is, 1 : 1
That means,
![\frac{0.760}{[M+3(35.5)]}=\frac{1.610}{[M+3(126.9)]}](https://tex.z-dn.net/?f=%5Cfrac%7B0.760%7D%7B%5BM%2B3%2835.5%29%5D%7D%3D%5Cfrac%7B1.610%7D%7B%5BM%2B3%28126.9%29%5D%7D)
![\frac{0.760}{[M+106.5]}=\frac{1.610}{[M+380.7]}](https://tex.z-dn.net/?f=%5Cfrac%7B0.760%7D%7B%5BM%2B106.5%5D%7D%3D%5Cfrac%7B1.610%7D%7B%5BM%2B380.7%5D%7D)
From this we conclude that the element (X) is lanthanum (La) that has molecular weight, 138.667 g/mol.
Hence, the chemical symbol for this element is, (La)
Answer:
1.63425 × 10^- 18 Joules.
Explanation:
We are able to solve this kind of problem, all thanks to Bohr's Model atom. With the model we can calculate the energy required to move the electron of the hydrogen atom from the 1s to the 2s orbital.
We will be using the formula in the equation (1) below;
Energy, E(n) = - Z^2 × R(H) × [1/n^2]. -------------------------------------------------(1).
Where R(H) is the Rydberg's constant having a value of 2.179 × 10^-18 Joules and Z is the atomic number= 1 for hydrogen.
Since the Electrons moved in the hydrogen atom from the 1s to the 2s orbital,then we have;
∆E= - R(H) × [1/nf^2 - 1/ni^2 ].
Where nf = 2 = final level= higher orbital, ni= initial level= lower orbital.
Therefore, ∆E= - 2.179 × 10^-18 Joules× [ 1/2^2 - 1/1^2].
= -2.179 × 10^-18 Joules × (0.25 - 1).
= - 2.179 × 10^-18 × (- 0.75).
= 1.63425 × 10^- 18 Joules.
It depends on the form it takes and how its formed. If raw carbon is in extreme pressure it can make a diamond. Graphite, however is made in a different way.
