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3 years ago

Help meh plz!!!

Chemistry

2 answers:

exis [7]3 years ago

3 0

D excretory system releases waste like when you use the bathroom and stuff. :)

Genrish500 [490]3 years ago

3 0

<span>D. excretory system...</span>

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Describe what the isotopes of an element have in common and how are they different.

Neporo4naja [7]

Answer:

Isotopes of an element are atoms of the same element that have different number of neutrons.

8 0

3 years ago

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Calculate the unit cell edge length for an 78 wt% Ag- 22 wt% Pd alloy. All of the palladium is in solid solution, and the crysta

BaLLatris [955]

Answer:

The unit cell edge length for the alloy is 0.405 nm

Explanation:

Given;

concentration of Ag, $C_{Ag}$ = 78 wt%

concentration of Pd, $C_P_d$ = 22 wt%

density of Ag = 10.49 g/cm³

density of Pd = 12.02 g/cm³

atomic weight of Ag, $A_A_g$ = 107.87 g/mol

atomic weight of iron, $A_P_d$ = 106.4 g/mol

Step 1: determine the average density of the alloy

$\rho _{Avg.} = \frac{100}{\frac{C_A_g}{\rho _A_g} + \frac{C__{Pd}}{\rho _{Pd}} }$

$\rho _{Avg.} = \frac{100}{\frac{78}{10.49} + \frac{22}{12.02} } = 10.79 \ g/cm^3$

Step 2: determine the average atomic weight of the alloy

$A _{Avg.} = \frac{100}{\frac{C_v}{A _A_g} + \frac{C__{Pd}}{A _{Pd}} }$

$A _{Avg.} = \frac{100}{\frac{78}{107.87} + \frac{22}{106.4} } = 107.54 \ g/mole$

Step 3: determine unit cell volume

$V_c=\frac{nA_{avg.}}{\rho _{avg.} N_a}$

for a FCC crystal structure, there are 4 atoms per unit cell; n = 4

$V_c=\frac{4*107.54}{ 10.79*6.022*10^{23}} = 6.620*10^{-23} \ cm^3/cell$

Step 4: determine the unit cell edge length

Vc = a³

$a = V_c{^\frac{1}{3} }\\\\a = (6.620*10^{-23}}){^\frac{1}{3}}\\\\a = 4.05 *10^{-8} \ cm$ = 0.405 nm

Therefore, the unit cell edge length for the alloy is 0.405 nm

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3 years ago

Which of these would be a good topic for a descriptive investigation? A. how the Moon's appearance changes B. what kind of dog f

katen-ka-za [31]

A. how the Moon's appearance changes

Explanation:

Descriptive investigation use very careful observations and measurements to develop findings.

Most geologists, meteorologists and astronomers use descriptive investigation to develop their findings.

Since most of their subject matter is inaccessible.
Descriptive investigation is used for indirectly making inquiries
It involves the development of an inquiry without formulating any hypothesis.

learn more:

Experiments brainly.com/question/1621519

#learnwithBrainly

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3 years ago

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An artificial reef is intended to affect the ocean ecosystem by — А A removing pollution from the water B В providing shelter fo

Mama L [17]

Annswer is B Explanation:acording to this diagram i f

gffgdffdggfdfgd

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3 years ago

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The balanced half-reaction in which sulfate ion is reduced to sulfite ion is a ________ process. Group of answer choices a) four

Aleks [24]

Answer:

The balanced half-reaction in which sulfate ion is reduced to sulfite ion is a two electron process

Explanation:

In the sulfate anion, S, acts with +6 in the oxidation number

SO₄⁻²

This is the anion from the sulfuric acid, when it lost the 2 protons

H₂SO₄ → 2H⁺ + SO₄⁻²

In the sulfite anion, S, acts with +4 in the oxidation number.

SO₃⁻²

This is the anion, generated when the sulfurose acid lost the 2 protons.

H₂SO₃ → SO₃⁻² + 2H⁺

In acidic medium

2H⁺ + SO₄⁻² + 2e⁻ → SO₃⁻² + H₂O

In basic medium

H₂O + SO₄⁻² + 2e⁻ → SO₃⁻² + 2OH⁻

7 0

3 years ago