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.
Answer:
3.29 × 10²⁸ Atoms
Solution:
Moles and Number of atoms are related to each other as,
Moles = Number of Atoms / 6.022 × 10²³ ------- (1)
Data Given;
Moles = 5.472 ×10⁴
Number of Atoms = ?
Solving eq. 1 for Number of Atoms,
Number of Atoms = Moles × 6.022 × 10²³
Putting values,
Number of Atoms = 5.472 ×10⁴ mol × 6.022 × 10²³ atoms.mol⁻¹
Number of Atoms = 3.29 × 10²⁸ Atoms
It becomes ionized and attains its stable electronic configuration.
Atomic number should be the answer
E = hc/(lamda)
The lamda symbol is wavelength, which this site does not have. I can represent it with an "x" instead.
Plancks constant, h = 6.626×10^-32 J·s
Speed of light, c = 3.00×10^8 m/s
The energy must be greater than or equal to 1×10^-18 J
1×10^-18 J ≤ (6.626×10^-32 J·s)*(3.0×10^8 m/s) / x
x ≤ (6.626×10^-32 J·s)*(3.0×10^8 m/s) / (1×10^-18 J)
x ≤ 1.99×10^-7 m or 199 nm
The wavelength of light must be greater than or equal to 199 nm
