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3 years ago

Particle Mass

Chemistry

1 answer:

dimaraw [331]3 years ago

5 0

Answer:

(i) Protons, Neutrons

(ii) Mass number = 15

(iii) Atomic number = 12

(iv) Neutrons present in the atom = 17

(v) Nuclear symbol for the silicon isotope with mass number, A = 29 is ²⁹₁₄Si

Explanation:

(i) An atom is composed of three fundamental sub-particles: electrons, protons and neutrons. Electrons are found in orbits or energy levels some distance away from The nucleus of the atom. The nucleus of an atom contains the protons and neutrons which accounts for the mass of the atom.

(ii) The mass number of an atom of an element is the sum of the protons and neutrons present jn the nucleus of the atom.

The mass number of an atom of oxygen with proton or atomic number 8 and neutron number 7 is 8 + 7 = 15

(iii) Atomic number of an atom of an element is equal to the number of protons in the atom of the element.

Mass number = proton number + neutron number

Proton number = mass number - proton number

Proton number = 25 - 13 = 12

(iv) In the atom of sulfur represented bymthe symbol, the number in superscript is the mass number A, and the number in subscript is the atomic number Z.

Mass number = proton number + neutron number

Neutron number = Mass number - proton number

Neutron number = 33 - 16 = 17

(v) The nuclear symbol for the silicon isotope with mass number, A = 29 is ²⁹₁₄Si

Where the number in superscript is the mass number A, and the number in subscript is the atomic number Z.

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Svet_ta [14]

Answer:

$\Delta S^{0}$ for the reaction is -198.762 J/K

Explanation:

$N_{2}(g)+3H_{2}(g)\rightarrow 2NH_{3}(g)$

Standard change in entropy for the system ( $\Delta S^{0}$ ) is given by-

$\Delta S^{0}=[2moles\times S^{0}(NH_{3})_{g}]-[1mole\times S^{0}(N_{2})_{g}]-[3\times S^{0}(H_{2})_{g}]$

where $S^{0}$ represents standard entropy.

Here $S^{0}(NH_{3})_{g}=192.45J/(K.mol)$ , $S^{0}(N_{2})_{g}=191.61J/(K.mol)$ and $S^{0}(H_{2})_{g}=130.684J/(K.mol)$

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3 years ago

A high school girl was getting ready for a big date but discovered with horror that her silver necklace was tarnished. having ju

OLga [1]

Answer:

a. What makes this an oxidation-reduction reaction? (1 point)

Loss of electron by the aluminum and the gain of electron by the silver

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oxidation half reaction: Al → Al3+ + 3e-

Reduction half reaction: Ag+ + e- → Ag

c. What is oxidized in the reaction? What is reduced? (2 points)

Aluminum is oxidized and silver is reduced

d. In this simple electrochemical cell, what functions as the anode? What is the cathode? (3 points)

In a simple electrochemical cell the electrode where oxidation takes place is the anode. And the electrode where reduction reaction happens is the cathode.

e. Is this a galvanic cell or electrolytic cell? Explain your answer. (2 points)

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2 years ago

Even at high T, the formation of NO is not favored:

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Answer:

3,16x10⁻³M

Explanation:

For the reaction:

N₂(g) + O₂(g) ⇄ 2NO(g). The kc is defined as:

kc = [NO]² / [N₂] [O₂] = 4,10x10⁻⁴ (1)

If you add in a 1,0L container 0,25 mol of N₂ and 0,10 mol of O₂, concentrations in equilibrium will be:

[N₂] = 0,25M - x

[O₂] = 0,10M - x

[NO] = 2x

Replacing in (1):

[2X]² / [0,25-x] [0,10-x] = 4,10x10⁻⁴

[2X]² / 0,025 - 0,35x + x²= 4,10x10⁻⁴

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3,99959x² + 1,435x10⁻⁴x - 1,025x10⁻⁵ = 0

Solving for x:

x = -0,0016 (Wrong answer, there is no negative concentrations)

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I hope it helps!

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4 years ago

Which atomic model proposed that electrons move in specific orbits around the nucleus of an atom?

kakasveta [241]

The Bohr Model, which was proposed by Niels Bohr in 1913

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3 years ago

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qaws [65]

Answer: a. 6(3x2=6)

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D. 4

E. 6(3(2)=6)

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H. 4(2(1)+2(1)=2+2=4)

Explanation:

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= No of ligands X denticity

Denticity is nothing but type of ligands like mono,do and tetradentate ligands.

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3 years ago