If two objects repel from one another, what must be happening on the subatomic scale?

In h-atom if x is radius of first bohrs orbit de broglie wavelength of an atom in 3rd orbit is a.3πx b.6πx c.9x/2 d.x/2

Step2247 [10]

Answer:

can you type question properly.

5 0

3 years ago

Enzymes are proteins that speed up chemical reactions in the body how do they work

Mila [183]

The answer would be D, Enzymes are soluble protein molecules that can speed up chemical reactions in cells. These reactions include respiration, photosynthesis and making new proteins. For this reason enzymes are sometimes called biological catalysts.

5 0

4 years ago

Determine the average rate of the reaction between 0 and 50 seconds.

o-na [289]

The answer to this question is D.

4 0

3 years ago

Why is it hard to create a completely closed system?

Rashid [163]

To put it simply, this law states that in a closed system, energy cannot be created or destroyed, but it can be converted from one form to another. A closed system is a system that does not interact with other systems or one that is contained.

Let’s imagine a pot of water on the stove. It has a lid, so it is not interacting with other systems, and for the purposes of this example, let’s imagine that the lid seals perfectly. When you turn on the burner, you are adding energy to the water in the form of heat. That heat will enter the water. Once it is there, it will be converted as it is absorbed by the water, which will begin to boil as a result. As the water boils, some of that energy will separate the water into gas, or steam. That steam collects on the underside of the pot lid and forms droplets that return to the water.

In reality, a pot cannot be a completely closed system. If you have boiled water, you will have seen steam escaping along the edges of the lid. It is a good thing that the pot is not perfectly closed because letting off steam is what keeps the pot from exploding as the heat, and consequently the pressure, builds. When you take the lid off a pot that is boiling, you immediately open the system and allow the heat to escape and be converted as water molecules escape into the air. If heat is constantly added to a closed system, it will build pressure as the molecules move faster and faster. Enough pressure can cause a pot to explode because all of that energy has nowhere to go and will eventually push the boundaries of the system.

While the atmosphere is not a perfectly closed system, in many ways it acts as if it were. Much of the gases on the planet will move continuously around the troposphere, creating weather. Some of those gas molecules will escape into the far reaches of the atmosphere, which is why it cannot be a closed system. But if we think about the way the gases are cycled through the ocean and the atmosphere, it is helpful to keep the law of conservation of energy in mind.

So therefore the answer is D) It is very difficult to have a system in which no outside gases enter. 

4 0

3 years ago

Use Hess's Law to determine the enthalpy change (∆H) for the reaction: ClF + F2 → ClF3 Given: 2ClF + O2 → Cl2O + F2O. ∆H=167.4kJ

emmasim [6.3K]

Answer:

The enthalpy change (∆H) for the reaction is -108.7 kJ

Explanation:

Hess's law can be stated as: when the reactants are converted to products, the enthalpy change is the same, regardless of whether the reaction is carried out in one step or in a series of steps. Then, Hess's Law states that the enthalpy of one reaction can be achieved by algebraically adding the enthalpies of other reactions.

So, to calculate the ∆H (heat of reaction) of the combustion reaction, that is, the heat that accompanies the entire reaction, you must make the total sum of all the heats of the products and of the reagents affected by their stoichiometric coefficient ( number of molecules of each compound participating in the reaction) and finally subtract them.

Enthalpy of combustion = ΔH = ∑Hproducts - ∑Hreactants

2 ClF + O₂ → Cl₂O + F₂O ∆H=167.4kJ

Cl₂O + 3 F₂O → 2 ClF₃ + 2 O₂ ∆H= -341.4kJ

The previous equation must be inverted, and the enthalpy value is also inverted, that is, the sign is changed.

2 F₂ + O₂ →2 F₂O ∆H=-43.4kJ

Reactants and products are added or canceled, taking into account that certain substances sometimes appear as a reagent and others as a product, so they are totally eliminated (there is nothing left of them anywhere in the reaction, if the same amount in reagents and products) or partially (this substance remains, in less quantity, only on one side), obtaining:

2 ClF + 2 F₂ → 2 ClF₃

Then, as all the reactants and products have a stoichiometric coefficient of 2, dividend by that number is obtained:

ClF + F₂ → ClF₃

Adding the enthalpies algebraically, and dividing by 2, because to get the "data" reaction you had to multiply by two, you get:

ΔH= [167.4 kJ - 341.4 kJ - 43.3 kJ]÷2

ΔH= -108.7 kJ

The enthalpy change (∆H) for the reaction is -108.7 kJ

3 0

4 years ago