Answer:

Explanation:
We have to remember the <u>molarity equation</u>:

So, we have to calculate "mol" and "L". The total volume is 100 mL. So, we can do the <u>conversion</u>:

Now we can calculate the moles. For this we have to calculate the <u>molar mass</u>:
O: 16 g/mol
H: 1 g/mol
C: 12 g/mol

With the molar mass value we can <u>calculate the number of moles</u>:

Finally, we can <u>calculate the molarity</u>:

I hope it helps!
Potassium has twenty neutrons
Answer:
E = 6.27 × 10⁻²³ Joules
Explanation:
E = h (Plancks constant) × f (frequency)
(Plancks constant = 6.63 × 10⁻³⁴ J×s)
f = λ × c (used to find frequency so you can satisfy energy equation)
*Have to find wavelength in meters to multiply by speed of light*
1. f = (3.15 × 10⁻⁷ m) × (3 × 10⁸ m/s)
2. f = 9.45 × 10¹⁰ s
3. E = (6.63 × 10⁻³⁴ J×s [Plancks constant]) × (9.45 × 10¹⁰ s)
E = 6.27 × 10⁻²³ Joules
Answer:
i think it is d hope this helps
The question is incomplete. Here is the complete question.
An atom of lead has a radius of 154 pm and the average orbitalspeed of the electron in it is about 1.8x
m/s. Calculate the least possible uncertainty in a measurement of the speed of an electron in an atom of lead. Write your answer as a percentage of the average speed, and round it to significant 2 digits.
Answer: v% = 0.21 m/s
Explanation: To calculate the uncertainty, use <u>Heisenberg's Uncertainty Principle</u>, which states that: ΔpΔx≥
where h is <u>Planck's constant</u> and it is equal to 6.626.
m²kg/s.
Since p (momentum) is p = m.v:
mΔv.Δx ≥ 
Δv = 
Given that: r = x = 1.54.
m and mass of an electron is m=9.1.
kg
Δv = 
Δv = 0.0376.
As percentage of average speed:
Δv.
.100% =
.10² = 0.021.10 = 0.21%
The least possible uncertainty in a speed of an electron is 0.21%.