Which element has atoms with only one completely filled principal energy level

The distance from the sun to earth would be ______.

Dvinal [7]

C- more than one light year or B-exactly one light year

8 0

2 years ago

The figure above shows the Earth at two different positions in its orbit around the Sun. Which position corresponds to summer in

Lelu [443]

Answer:

A. Position B.

Explanation:

In the summer the northern hemisphere is closer to the Sun so it's Position B.

3 0

2 years ago

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formic acid buffer containing 0.50 M HCOOH and 0.50 M HCOONa has a pH of 3.77. What will the pH be after 0.010 mol of NaOH has b

HACTEHA [7]

Answer:

pH = 3.95

Explanation:

It is possible to calculate the pH of a buffer using H-H equation.

pH = pka + log₁₀ [HCOONa] / [HCOOH]

If concentration of [HCOONa] = [HCOOH] = 0.50M and pH = 3.77:

3.77 = pka + log₁₀ [0.50] / [0.50]

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Knowing pKa, the NaOH reacts with HCOOH, thus:

HCOOH + NaOH → HCOONa + H₂O

That means the NaOH you add reacts with HCOOH producing more HCOONa.

Initial moles of 100.0mL = 0.1000L:

[HCOOH] = (0.50mol / L) ₓ 0.1000L = 0.0500moles HCOOH

[HCOONa] = (0.50mol / L) ₓ 0.1000L = 0.0500moles HCOONa

After the reaction, moles of each species is:

0.0500moles HCOOH - 0.010 moles NaOH (Moles added of NaOH) = 0.0400 moles HCOOH

0.0500moles HCOONa + 0.010 moles NaOH (Moles added of NaOH) = 0.0600 moles HCOONa

With these moles of the buffer, you can calculate pH:

pH = 3.77 + log₁₀ [0.0600] / [0.0400]

3 0

3 years ago

_P4 + ____O2 → __P2O3<br><br> How do I balance this equation?

Murljashka [212]

Explanation:

please mark me as brainlest

5 0

2 years ago

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In Universe , recently discovered by an intrepid team of chemists who also happen to have studied interdimensional travel, quant

tiny-mole [99]

Answer:

Check the explanation

Explanation:

When talking about our universe there are 5 d orbitals. The element of first transition series moves away from the universal principles of Hund's rule and Aufbav's principle. So in order to attain stability these elements tend to form half or full filled orbitals.

In our universe the ground state electronic configuration of sixth transition metal, Iron (Fe) : [Ar] $3d^{6} 4s^{2}$

and the electronic configuration of seventh transition metal, Cobalt (Co) : [Ar] $3d^{7} 4s^{2}$

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In universe L there are seven orbitals.

Ground state electronic configuration of sixth and seven transition element.

Sixth transition metal: [Ar] $3d^{7} 4s^1 or [X] 3d^{7} 4s^1$

Seventh transition metal: [Ar] $3d^{7} 4s^{2}or [X] 3d^{7} 4s^{2}$

7 0

2 years ago