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:
<h2>12.38 g/mL</h2>
Explanation:
The density of a substance can be found by using the formula

m is the mass
v is the volume
From the question
m = 149.8 g
v = 12.1 mL
We have

We have the final answer as
<h3>12.38 g/mL</h3>
Hope this helps you
Making repeated separations of the various substances in the pitchblende, Marie and Pierre used the Curie electrometer to identify the most radioactive fractions. They thus discovered that two fractions, one containing mostly bismuth and the other containing mostly barium, were strongly radioactive.
<h3>What was surprising about pitchblende?</h3>
Since it was no longer appropriate to call them “uranic rays,” Marie proposed a new name: “radioactivity.”
Even more surprising, Marie next found that a uranium ore called pitchblende contained two powerfully radioactive new elements: polonium, which she named for her native Poland, and radium.
<h3>Why is radium more radioactive than uranium?</h3>
It is 2.7 million times more radioactive than the same molar amount of natural uranium (mostly uranium-238), due to its proportionally shorter half-life.
Learn more about highly radioactive elements here:
<h3>
brainly.com/question/10257016</h3><h3 /><h3>#SPJ4</h3>
Answer:
The value of the equilibrium constant (K) remains the same.
Explanation:
A state of dynamic equilibrium is said to have been achieved in a reaction system when the rate of forward reaction equals the rate of reverse reaction.
At equilibrium, doubling the initial concentration of reactants have no effect on the equilibrium constant K. The equilibrium will rather shift to the left or right as required in order to annul the constraint.
D= mass over volume
So, density equals 9.0g divided by 45ml.
SO, D=.25 g/ml
I'm not 100% sure this is correct, though. Best if luck. ♡