Answer:
810 pm
Explanation:
Step 1: Given and required data
- Velocity of the atom (v): 490 m/s
- Mass of a hydrogen atom (m): 1.67 × 10⁻²⁷ kg
- Planck's constant (h): 6.63 × 10⁻³⁴ J.s
Step 2: Calculate the de Broglie wavelength of the hydrogen atom
We will use de Broglie's equation.
λ = h / m × v
λ = 6.63 × 10⁻³⁴ J.s / 1.67 × 10⁻²⁷ kg × 490 m/s = 8.10 × 10⁻¹⁰ m
Step 3: Convert 8.10 × 10⁻¹⁰ m to picometers
We will use the conversion factor 1 m = 10¹² pm.
8.10 × 10⁻¹⁰ m × 10¹² pm/1 m = 810 pm
Answer:
Explanation:
A gives off a visible gaseous product when the two are mixed.
The others all talk about physical properties like phase changes and densities.
Answer: pH of an 
solution is 4.34
Explanation:
pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration.
![pH=-\log [H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D)
Putting in the values:
![pH=-\log[4.58\times 10^{-5}]](https://tex.z-dn.net/?f=pH%3D-%5Clog%5B4.58%5Ctimes%2010%5E%7B-5%7D%5D)
Thus pH of an solution if the ![[H^+]](https://tex.z-dn.net/?f=%5BH%5E%2B%5D)
is ![4.58\times 10^{-5}]](https://tex.z-dn.net/?f=4.58%5Ctimes%2010%5E%7B-5%7D%5D)
is 4.34
Explanation:
A physical change is change that alters the physical properties of matter especially its form and state.
In many cases, the change is easily reversible.
Examples are change of state such as boiling, melting, freezing, condensation, sublimation e.t.c
A chemical change is one in which a new kind of matter is formed. It is always accompanied by energy changes.
Examples are combustion, rusting , precipitation, milk souring.
- Chemical changes are irreversible
- Physical changes do not lead to the formation of new kinds of matter.
- Most physical changes requires little energy.
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Chemical change brainly.com/question/9388643
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