By wave particle duality.
Wavelength , λ = h / mv
where h = Planck's constant = 6.63 * 10⁻³⁴ Js, m = mass in kg, v = velocity in m/s.
m = 1kg, v = 4.5 m/s
λ = h / mv
λ = (6.63 * 10⁻³⁴) /(1*4.5)
λ ≈ 1.473 * 10⁻³⁴ m
Option D.
Answer: 0.049 mol
Explanation:
1) Data:
n₁ = 0.250 mol
p₁ = 730 mmHg
p₂ = 1.15 atm
n₂ - n₁ = ?
2) Assumptions:
i) ideal gas equation: pV = nRT
ii) V and T constants.
3) Solution:
i) Since the temperature and the volume must be assumed constant, you can simplify the ideal gas equation into:
pV = nRT ⇒ p/n = RT/V ⇒ p/n = constant.
ii) Then p₁ / n₁ = p₂ / n₂
⇒ n₂ = p₂ n₁ / p₁
iii) n₂ = 1.15atm × 760 mmHg/atm × 0.250 mol / 730mmHg = 0.299 mol
iv) n₂ - n₁ = 0.299 mol - 0.250 mol = 0.049 mol
<h3><u>Answer;</u></h3>
D) Standing wave
<h3><u>Explanation;</u></h3>
- Standing wave also called stationary wave is a wave which oscillates in time but whose peak amplitude profile does not move in space.
- A standing wave pattern is a vibrational pattern created within a medium when the vibrational frequency of the source causes reflected waves from one end of the medium to interfere with incident waves from the source.
- Examples of standing waves include the vibration of a violin string and electron orbitals in an atom.
I added individual steps for clarity. Note that g must be positive if the solution is to be real.

Let me know if you have any questions.
It should be 0.25kg because you converter from g to kg and since 1g<1kg so you move the decimal to the left