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3 years ago

What element in the fourth period is an exception to the Aufbau principle? a. Li c. Ca b. Cr d. Br

1 answer:

4 0

The fourth period contains 18 elements, beginning with potassium and ending with krypton. As a rule, period 4 elements fill their 4s shells first, then their 3d and 4p shells, in that order; however, there are exceptions, such as chromium.

Cr. I think

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A nitrogen atom has five valence electrons. The Lewis structure shows how a nitrogen atom bonds with three hydrogen atoms to for

nordsb [41]

It has too be 6 or 4

3 0

2 years ago

Balance NaOH + H3PO4->H2O + Na3PO4

Masteriza [31]

Answer:

3NaOH + H3PO4 ---> 3H2O + Na3PO4

Explanation:

7 0

2 years ago

Why does potassium explode when exposed to water?

soldi70 [24.7K]

Answer:

The highly unstable pure sodium or potassium wants to lose an electron and this splits the water atom, producing a negatively charged hydroxide ion and hydrogen and forming an explosive gas that ignites.

Explanation:

4 0

2 years ago

When aqueous solutions of manganese(II) iodide and sodium phosphate are combined, solid manganese(II) phosphate and a solution o

Feliz [49]

Answer:

The net ionic equation for the given reaction :

$3Mn^{2+}(aq)+2PO_4^{3-}(aq)\rightarrow Mn_3(PO_4)_2(s)$

Explanation:

$3MnI_2(aq)+2Na_3PO_4_2(aq)\rightarrow Mn_3(PO_4)_2(s)+6NaI(aq)$ ...[1]

$MnI_2(aq)\rightarrow Mn^{2+}(aq)+2I^-(aq)$ ..[2]

$Na_3PO_4(aq)\rightarrow 3Na^{+}(aq)+PO_4^{3-}(aq)$ ...[3]

$NaI(aq)\rightarrow Na^+(aq)+I^-(aq)$

Replacing $MnI_2(aq)$ , NaI and $Na_3PO_4(aq)$ in [1] by usig [2] [3] and [4]

$3Mn^{2+}(aq)+6I^-(aq)+6Na^{+}(aq)+2PO_4^{3-}(aq)\rightarrow Mn_3(PO_4)_2(s)+6Na^+(aq)+6I^-(aq)$

Removing the common ions present ion both the sides, we get the net ionic equation for the given reaction [1]:

$3Mn^{2+}(aq)+2PO_4^{3-}(aq)\rightarrow Mn_3(PO_4)_2(s)$

8 0

2 years ago

A student has a sample of 1.33 moles of fluorine gas that is contained in a 23.3 L container at 314 K. What is the pressure of t

Gelneren [198K]

1.4715 atm is the pressure of the sample 1.33 moles of fluorine gas that is contained in a 23.3 L container at 314 K.

What is an ideal equation?

The ideal gas equation, pV = nRT, is an equation used to calculate either the pressure, volume, temperature or number of moles of a gas. The terms are: p = pressure, in pascals (Pa).

Given data:

Volume (V) = 23.3 L

Number of mole (n) = 1.33 moles

Temperature (T) = 314 K

Gas constant (R) = 0.821 atm.L/Kmol

Pressure (P) =?

The pressure inside the container can be obtained by using the ideal gas equation as illustrated below:

PV = nRT

P × 23.3 L = 1.33 moles × 0.0821 ×314 K

P = 1.4715 atm

Therefore, the pressure of the sample is 1.4715 atm.

Learn more about the ideal gas equation:

brainly.com/question/23826793

SPJ1

4 0

1 year ago