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3 years ago

What information can be learned about atoms of different elements by examining the periodic table

Chemistry

1 answer:

7nadin3 [17]3 years ago

4 0

Answer:

The periodic table tells you the atomic number (which tells you the number of protons and electrons). It also includes the mass number, which is the sum of the protons and neutrons in the nucleus of an atom.

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The quantum mechanical model of the atom

ollegr [7]

No two electrons in an atom<span> can have exactly the same </span>quantum<span> numbers. Orbital </span>quantum<span> numbers tell you what energy level the electron is in. In the Bohr</span>model<span>, this represents how high the orbit is above the nucleus; higher orbits have more energy</span>

6 0

3 years ago

Read 2 more answers

How many seconds does it take to deposit 0.94 g of Ni on a decorative drawer handle when 14.9 A is passed through a Ni(NO3)2 sol

Goshia [24]

Answer:

Time take to deposit Ni is 259.02 sec.

Explanation:

Given:

Current $I = 14.9$ A

Faraday constant $= 96485$ $\frac{C}{mole}$

Molar mass of Ni $= 58.69$ $\frac{g}{mole}$

Mass of Ni $= 0.94$ g

First find the no. moles in Ni solution,

Moles of Ni $= \frac{0.94}{58.69}$

$= 0.02$ mol

From the below reaction,

$Ni^{2+} + 2e$ ⇆ $Ni_{(s)}$

Above reaction shows "1 mol of $Ni^{2+}$ requires 2 mol of electron to form 1 mol of $Ni_{(s)}$ "

So for finding charge flow in this reaction we write,

$=$ $0.02 \times \frac{2 }{1 } \times 96485 \frac{C}{mol}$

Charge flow $= 3859.4$ C

For finding time of reaction,

$I = \frac{q}{t}$

Where $q =$ charge flow

$t = \frac{q}{I}$

$t = \frac{3859.4}{14.9}$

$t = 259.02$ sec

Therefore, time take to deposit Ni is 259.02 sec.

3 0

3 years ago

For the following reactions, write a balanced equation using half-reactions and calculate the voltage to be expected.

Iteru [2.4K]

a) $2Na(s) +2H_2O(I)$ → $2Na^+(aq) + OH^-(aq)+ H_2(g)$

b) $2Ag (s) +2H^(aq)$ → $2 Ag^+ (aq) +H_2(g)$

<h3>What are half-reactions?</h3>

The half-reaction method is a way to balance redox reactions. It involves breaking the overall equation down into an oxidation part and a reduction part.

$2Na(s) +2H_2O(I)$ → $2Na^+(aq) + OH^-(aq)+ H_2(g)$

$E^0 cell = E^0 (reduction) - E^0 (oxidation)$

= $E^0(\frac{H_2O}{H_2}, OH^-) -E^0(Na^+/Na)$

= -0.83 - (-2.71) =1.88V

$2Ag (s) +2H^(aq)$ → $2 Ag^+ (aq) +H_2(g)$

$E^0cell$ = $E^0(H^+/H_2) -E^0(Ag^+/Ag)$

$E^0cell$ =-0. - (0.8) =-0.8V

Learn more about the half-reactions here:

https://brainly.in/question/18053421

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8 0

2 years ago

How do the number of protons in an atom affect the atom's<br> identity?

fredd [130]

Answer:

The number of protons in an atom define each individual element because the number of protons is the atomic number which is the defining property of an atom and never changes. The number of protons determines an atom's identity. For example, Oxygen has an atomic number of 8, so it has 8 protons, so no matter what ionic compound or molecule it's part of, every single Oxygen atom will always have 8 protons each.

6 0

3 years ago

PLEASE ANSWER I AM BEGGING

TiliK225 [7]

Taking into account the definition of dilution:

you have to use 8.23 mL of a stock solution of 7.00 M HNO₃ to prepare 0.120 L of 0.480 M HNO₃.
If you dilute 20.0 mL of the stock solution to a final volume of 0.270 L , the concentration of the diluted solution is 0.518 M.

<h3>Dilution</h3>

Dilution is the process of reducing the concentration of solute in solution, which is accomplished by simply adding more solvent to the solution at the same amount of solute.

In a dilution the amount of solute does not change, but as more solvent is added, the concentration of the solute decreases, as the volume (and weight) of the solution increases.

A dilution is mathematically expressed as:

Ci×Vi = Cf×Vf

where

Ci: initial concentration
Vi: initial volume
Cf: final concentration
Vf: final volume

<h3>Volume of stock solution</h3>

In this case, you know:

Ci= 7 M
Vi= ?
Cf= 0.480 M
Vf= 0.120 L

Replacing in the definition of dilution:

7 M× Vi= 0.480 M× 0.120 L

Solving:

Vi= (0.480 M× 0.120 L)÷ 7 M

<u><em>Vi= 0.00823 L= 8.23 mL</em></u> (being 1 L= 1000 mL)

Finally, you will need 8.23 mL of the stock solution.

<h3>Concentration of the diluted solution</h3>

In this case, you know:

Ci= 7 M assuming the stock solution is 7.00 M HNO₃
Vi= 20 mL= 0.02 L
Cf= ?
Vf= 0.270 L

Replacing in the definition of dilution:

7 M× 0.02 L= Cf× 0.270 L

Solving:

(7 M× 0.02 L)÷ 0.270 L= Cf

Finally, the concentration is 0.518 M.

Learn more about dilution:

brainly.com/question/13505906

brainly.com/question/6692004

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brainly.com/question/24709069

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5 0

1 year ago