Answer:
7.5 × 10¹⁵ Hz
Explanation:
Given data
- Wavelength of the radio waves (λ): 40 nm = 40 × 10⁻⁹ m = 4.0 × 10⁻⁸ m
- Frequency of the radio waves (ν): ?
- Speed of light (c): 3.00 × 10⁸ m/s
We can determine the frequency of the radio waves using the following expression.
c = λ × ν
ν = c/λ
ν = (3.00 × 10⁸ m/s)/4.0 × 10⁻⁸ m
ν = 7.5 × 10¹⁵ s⁻¹ = 7.5 × 10¹⁵ Hz
Since O almost always has a charge of -2, the oxygen atoms have an overall charge of -8 (-2*4)
Since K has a charge of +1, that brings the overall charge to -7 (-8+1)
Then, in order for the overall charge to be 0, Mn would have to have a change of +7 (-7+7=0)
Hope this helps
<span>Water:
*can dissolve most substances
* contains dissolved minerals
*expands when it freezes</span>
<span>The half life of americium is 432 years. That means that after 432 years only half(1/2) of initial amount will be left.
If we had 1 g, then after 432 years we will have only half of it.
1g*1/2=1/2 g=0.5 g
Answer is </span><span>A) 0.5g</span>