What is a property of all atoms

Match these items. 1 . Niels Bohr negative charge 2 . n=1 shell basic unit of matter 3 . electron electron path 4 . electron clo

steposvetlana [31]

Answer: Niels Bohr - Drew first picture of atom

n=1 shell - inner orbit

electron - Negative charge

Electron cloud - 3D orbits

Proton - postive charge

Molecule - two or more atoms bonded

Orbit - electron path

John Dalton - Develope atomic theory

Explanation:

1. Niels Borh proposed an atom model taking into account quantum physics. In his model, he proposed that electrons orbit around the nucleus in limited areas and if they need energy to move between orbitals. Although this model has been modified according to recent discoveries, basic postulates remain, that is why is so important the Borh's model

2. n is the principal quantum number which correspond to the orbital of and atom. According to Bohr's model orbits are organized depending on the energy, obits with lower energy are closer to the nucleus and have lower quantum number, so n=1 represent the orbit which closer to the nucleus

3. An electron is a particle of the atom, is the smallest of them and it has negative charge that are attracted by the positive charge of protons, that is why they are orbiting the nucleus.

4. In modern model there is a principle of uncertainty that states that we can not know the speed and the position of an electron at the same time, so the orbits are consider as spaces or regions where is probable to find and electron. This regions are three dimentional as we conceive the world so they are compare to a cloud with negative charge

5. proton is the partice located in the nucleus of the atom. It was discovered by Rutherford who realized that this particles were attracted to negative charges, and takin into account that different charges attract each other, he concluded that protons have positive charge

6. molecules are the elemental part of a compound and they are made by the two or more atoms that bond through electrons

7 atom is the basic unit of matter because it has particular characteristics according to the number of protons and electrons. This units built all things known in the universe.

8. An orbit was consider by Borh as the path that the electron follows in order to remain closer to the nucleus. He proposed that is was a straigh path as the planets arroud the sun, but nowdays we know that elelctrons are considered in a 3D space that move arround the nucleus.

9. John Dalton is the scientist in modern era that proposed the existence of atoms after studing greek philosophers writings about matter. He proposed that atoms were the smallest unit of matter and the make all the things in nature. Acoording to him, the nature of the electron and the size of it made the diferent elements in the universe. His postulates are very important in science because open a new are of research for chemists and physicists

8 0

3 years ago

Air is compressed from an inlet condition of 100 kPa, 300 K to an exit pressure of 1000 kPa by an internally reversible compress

ElenaW [278]

Answer:

(a) $W_{isoentropic}=8.125\frac{kJ}{mol}$

(b) $W_{polytropic}=7.579\frac{kJ}{mol}$

(c) $W_{isothermal}=5.743\frac{kJ}{mol}$

Explanation:

Hello,

(a) In this case, since entropy remains unchanged, the constant $k$ should be computed for air as an ideal gas by:

$\frac{R}{Cp_{air}}=1-\frac{1}{k} \\\\\frac{8.314}{29.11} =1-\frac{1}{k}\\$

$0.2856=1-\frac{1}{k}\\\\k=1.4$

Next, we compute the final temperature:

$T_2=T_1(\frac{p_2}{p_1} )^{1-1/k}=300K(\frac{1000kPa}{100kPa} )^{1-1/1.4}=579.21K$

Thus, the work is computed by:

$W_{isoentropic}=\frac{kR(T_2-T_1)}{k-1} =\frac{1.4*8.314\frac{J}{mol*K}(579.21K-300K)}{1.4-1}\\\\W_{isoentropic}=8.125\frac{kJ}{mol}$

(b) In this case, since $n$ is given, we compute the final temperature as well:

$T_2=T_1(\frac{p_2}{p_1} )^{1-1/n}=300K(\frac{1000kPa}{100kPa} )^{1-1/1.3}=510.38K$

And the isentropic work:

$W_{polytropic}=\frac{nR(T_2-T_1)}{n-1} =\frac{1.3*8.314\frac{J}{mol*K}(510.38-300K)}{1.3-1}\\\\W_{polytropic}=7.579\frac{kJ}{mol}$

(c) Finally, for isothermal, final temperature is not required as it could be computed as:

$W_{isothermal}=RTln(\frac{p_2}{p_1} )=8.314\frac{J}{mol*K}*300K*ln(\frac{1000kPa}{100kPa} ) \\\\W_{isothermal}=5.743\frac{kJ}{mol}$

Regards.

8 0

2 years ago

which has a higher entropy for the reaction: 2nh3(g)→n2(g) 3h2(g) which has a higher entropy for the reaction: reactants product

krok68 [10]

The one that has a higher entropy for the reaction is products.

<h3>What is entropy?</h3>

Entropy is a measureable physical characteristic and a scientific notion that is frequently connected to a condition of disorder, unpredictability, or uncertainty. It is the measurement of the amount of thermal energy per unit of temperature in a system that cannot be used for productive work. It is a measure of a system's molecular disorder or unpredictability since work is produced by organized molecular motion.

It should bm be noted that the entropy of gas is more than entropy of aqueous which is more than the entropy of liquid and the entropy of solid.

On the product side there are more gas than the reactant side. Therefore, product has more entropy.

Learn more about entropy on:

brainly.com/question/6364271

#SPJ1

3 0

1 year ago

If you react 2.00 g of hydrogen completely using 15.87 g of oxygen to produce water, how much water (in grams) will you have?

leonid [27]

Answer:

The amount (mass) of water we will have is 17.869 grams

Explanation:

The molar mass of hydrogen gas H₂ = 2.016 grams/mole

The molar mass of oxygen gas = 31.999 g/mol

Therefore, 2.00 g of hydrogen will give;

2.00/2.016 = 0.9921 moles of H₂ gas and

15.87 g of O₂ will give;

15.87/31.999 = 0.49595 moles

The reaction is as follows;

2H₂ (g) + O₂ (g) → 2H₂O (l)

Two moles of H₂ react with one mole of O₂ to produce two moles of H₂O

Therefore 0.9921 moles of H₂ will react with 0.9921/2 or 0.49595 moles of O₂ to produce 0.9921 moles of H₂O

From the above we note that all the H₂ and O₂ are completely consumed to form 0.9921 moles of H₂O

Molar mass of H₂O = 18.01528 g/mol

Number of moles = Mass/(Molar mass)

∴ Mass of H₂O = (Molar mass) × (Number of moles)

= 18.01528 g/mol × 0.9921 moles = 17.869 grams

Therefore the amount (mass) of water we will have = 17.869 grams.

8 0

3 years ago

Which best explains how heat plays a role in the movement of materials within Earth's interior?

Tema [17]

Answer:

Hot material near Earth's surface is more dense and sinks, and when it cools, it becomes less dense and rises.

Explanation:

Convection is a process by which less dense material rises and more dense material sinks near Earth's surface. Water, air, rocks and other materials expands when temperature rises and they become less dense. When the water is heated it becomes vapors and carries away thermal energy from the water.

6 0

3 years ago

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