Answer:
14 ml of water
Explanation:
To find the volume you need to dilute the concentration of a solution, you should use the formula C1 x V1 = C2 x V2 in which:
C1 = initial concentration ( in this case 60 %)
V1 = initial volume ( in this case 70 ml)
C2 = Final concentration ( you want to dilute until 50 %)
V2 = final volume ( the variable you want to search)
So you need to:
1.- Isolate the variable you want to find: V2 = (C1 x V1) / C2
2.- Substitute data: V2 = (60% x 70 ml) /50 %
3.- You do the math, in this case is 84 ml.
4.- Remember that you have a initial volume of 70 ml, so the difference (84 ml - 70 ml = 14 ml) is the volume you need to add to dilute your solution.
Oxidation is basically lose of electron..
hope it helped
Answer: arrangement of constituent particles makes glass diff. from quartz. Glass-short range order of particles.
Quartz-Long range of particles.
If quartz is heated and cooled rapidly it can be converted to glass.
Answer:
The general equation for an exothermic reaction is: Reactants → Products + Energy.
Answer:
1.64x10⁻¹⁸ J
Explanation:
By the Bohr model, the electrons surround the nucleus of the atom in shells or levels of energy. Each one has it's energy, and the electron doesn't fall to the nucleus because it can reach another level of energy, and then return to its level.
When the electrons go to another level, it absorbs energy, and then, when return, this energy is released, as a photon (generally as luminous energy). The value of the energy can be calculated by:
E = hc/λ
Where h is the Planck constant (6.626x10⁻³⁴ J.s), c is the light speed (3.00x10⁸ m/s), and λ is the wavelength of the photon.
The wavelength can be calculated by:
1/λ = R*(1/nf² - 1/ni²)
Where R is the Rydberg constant (1.097x10⁷ m⁻¹), nf is the final orbit, and ni the initial orbit. So:
1/λ = 1.097x10⁷ *(1/1² - 1/2²)
1/λ = 8.227x10⁶
λ = 1.215x10⁻⁷ m
So, the energy is:
E = (6.626x10⁻³⁴ * 3.00x10⁸)/(1.215x10⁻⁷)
E = 1.64x10⁻¹⁸ J
