Answer:
See explanation
Explanation:
The question is incomplete because the images of the models are absent. However, i will try to give you a general description of what the correct answer should be.
Beryllium is a member of group 2 in the periodic table. Beryllium has an atomic number of 4. This implies that it has four protons in its nucleus and four electrons in its shells. In a neutral atom, the number of electrons on the shells is equal to the number of protons in the nucleus.
The electronic configuration of Beryllium is 1s2 2s2. This implies that it should have two shells each containing only two electrons each.
Since we are using white foam balls for protons and black foam balls for neutrons, the clear plastic will contain four white foam balls and five black foam balls since the mass number of beryllium is 9 and number of neutrons = mass number - number of protons.
Four blue foam balls hanging from strings will represent the electrons around the nucleus.
Any model that corresponds to the description above is the correct answer.
Answer & Explenation:
2H2 + O2 -> 2H20 is the balanced equation for the reaction of Hydrogen with Oxygen to form water so
If you have 32g of O2 this is a simple Dimensional analysis problem
32g O2 x 36.03056g H20/31.9988g O2 this way the O2 cancels out and you are left with just the H2O so your raw answer would be 36.0319112, then if your instructor requires a significant figure answer that would be to 2 significant figures the information you were given 32g O2, so as above 36g or Water are produced. Just a different way to view and solve the problem with the balanced equation so you can see the way everything relates to everything else. the molar masses of O2 and H2O are simply found my adding up 2 Oxygens 15.9994g x2 = 31.9988g and H2O = 2(1.00794) + 15.9994 = 18.01258 but you then have to multiply that by 2 because the reaction states you get 2 mols in the reaction so that is where I came up with the 36.03056g for the solution. Hope this helps. Dimensional Analysis is and can be one of the best ways to solve these problems, because not always are you going to be dealing with 1:2 ratios.
Electrons are orbiting around the nucleus in a specific energy level as described in Bohr's atomic model. There are 7 energy levels all in all; 1 being the strongest and nearest to the nucleus, and 7 being the weakest and farthest away from the nucleus. Electron can transfer from one energy level to another. If it increases energy, it absorbs energy. If it goes down an energy level, it emits energy in the form of light. This light can be measure in wavelength through the Rydberg equation:
1/λ =R(1/n₁² -1/n₂²), where
λ is the wavelength
R is the Rydberg constant equal to 1.097 × 10⁻7<span> per meter
n</span>₁ and n₂ are the energy levels such that n₂>n₁
In the Paschen series is an emission spectrum of hydrogen when the energy level is at least n=4. So, this covers n=4 to n=7.
1/λ =(1.097 × 10⁻7)(1/4² -1/7²)
λ = 216.57 ×10⁻⁶ m or 216.57 μm
The mole fraction of pentane in the vapor is 0.291
Vapour pressure rises with temperature and is a measurement of a substance's propensity to transform into a gaseous or vapour state. The boiling point of a liquid is the temperature at which the pressure exerted by its surroundings equals the vapour pressure present at the liquid's surface.
The number of moles of a particular component in the solution divided by the overall number of moles in the sample solution is known as the mole fraction.
Using the formula for vapour pressure,
vapour pressure =
°
×
+
°
× 
vapour pressure = 151 × 

+ 425 × 
240 = 151 - 151
+ 425
240 - 151 = - 151
+ 425 
89 = 274 
= 
0.291 = 
Therefore, the mole fraction of pentane in the vapor is 0.291
Learn more about vapour pressure here;
brainly.com/question/25699778
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