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4 years ago

What is the symbol for Lithium, Iron, and Helium

Chemistry

2 answers:

jonny [76]4 years ago

8 0

Lithium=li

Iron=Fe

Helium=He

I don't say u must have to mark my ans as brainliest but if u think it has really helped u plz don't forget to thank me....

Lemur [1.5K]4 years ago

4 0

Answer:

lithium symbol=li helium= he and iron =i

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Water found in animal and human cells is most often found in the (liquid, solid, gas plasma) phase of matter, and oxygen is foun

jarptica [38.1K]

Water found in animal and human cells is most often found in the liquid phase of matter, and oxygen is found in the gas plasma phase of matter. 

I hope my answer has come to your help. Thank you for posting your question here in Brainly. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!

4 0

3 years ago

The value of the equilibrium constant for the following chemical equation is Kr 40 at 25°C. Calculate the solubility of Al(OH)s(

dedylja [7]

Answer:

0,040 M

Explanation:

The global reaction of the problem is:

Al(OH) (s) + OH⁻ ⇄ Al(OH)₂⁻(aq) K= 40

The equation of equilibrium is:

K = $\frac{[Al(OH)_{2} ^-]}{[Al(OH)][OH^-]}$

The concentration of OH⁻ is:

pOH = 14 - pH = 3

pOH = -log [OH⁻]

[OH⁻] = 1x10⁻³

Thus:

40 = $\frac{[Al(OH)_{2} ^-]}{[Al(OH)][1x10^{-3}]}$

0,04M = $\frac{[Al(OH)_{2} ^-]}{[Al(OH)]}$ 

This means that 0,04 M are the number of moles that the solvent can dissolve in 1L, in other words, solubility.

I hope it helps!

7 0

3 years ago

Arrange the following H atom electron transitions in order of increasing frequency of the photon absorbed or emitted:

Temka [501]

The question is incomplete , complete question is:

Arrange the following H atom electron transitions in order of increasing frequency of the photon absorbed or emitted:

(a) n = 2 to n = 4

(b) n = 2 to n = 1

(d) n = 4 to n = 3

Answer:

Hence the order of the transition will be : d < a < c < b

Explanation:

$E_n=-13.6\times \frac{Z^2}{n^2}ev$

where,

$E_n$ = energy of $n^{th}$ orbit

n = number of orbit

Z = atomic number

Energy of n = 1 in an hydrogen atom:

$E_1=-13.6\times \frac{1^2}{1^2}eV=-13.6 eV$

Energy of n = 2 in an hydrogen atom:

$E_2=-13.6\times \frac{1^2}{2^2}eV=-3.40eV$

Energy of n = 3 in an hydrogen atom:

$E_3=-13.6\times \frac{1^2}{3^2}eV=-1.51eV$

Energy of n = 4 in an hydrogen atom:

$E_4=-13.6\times \frac{1^2}{4^2}eV=-0.85 eV$

Energy of n = 5 in an hydrogen atom:

$E_5=-13.6\times \frac{1^2}{5^2}eV=-0.544 eV$

a) n = 2 to n = 4 (absorption)

$\Delta E_1= E_4-E_2=-0.85eV-(-3.40eV)=2.55 eV$

b) n = 2 to n = 1 (emission)

$\Delta E_2= E_1-E_2=-13.6 eV-(-3.40eV)=-10.2 eV$

Negative sign indicates that emission will take place.

c) n = 2 to n = 5 (absorption)

$\Delta E_3= E_5-E_2=-0.544 eV-(-3.40eV)=2.856 eV$

d) n = 4 to n = 3 (emission)

$\Delta E_4= E_3-E_4=-1.51 eV-(-0.85 eV)=-0.66 eV$

Negative sign indicates that emission will take place.

According to Planck's equation, higher the frequency of the wave higher will be the energy:

$E=h\nu$

h = Planck's constant

$\nu$ frequency of the wave

So, the increasing order of magnitude of the energy difference :

$E_4$

And so will be the increasing order of the frequency of the of the photon absorbed or emitted. Hence the order of the transition will be :

: d < a < c < b

7 0

4 years ago

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Bas_tet [7]

Answer:

G. The velocity is not changing because the speed is constant.

Explanation:

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3 years ago

I don’t understand the difference

Andreas93 [3]

Answer: I am not sure about the answer, but I can help explain the difference.

Explanation:

The geocentric model says that the earth is at the center of the cosmos or universe, and the planets, the sun and the moon, and the stars circles around it. The early heliocentric models consider the sun as the center, and the planets revolve around the sun.

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4 years ago