Plzzzz answer quick

An excited electron of hydrogen emits the least energy when it drops from 1 point
quantum levels *
Level 4 to level 2
level 5 to level 1
level 2 to level 1
O level 2 to level 5

Answer:

A) Carbon

Explanation:

the others are wrong its A

Answer:

A) carbon

Explanation:

carbon or simply c has an atomic number of 6 and it has an atomic mass of 12.01 amu. it belongs to group 4a

Hey there !

Molecular Weight: 262.86 g/mol

Volume in liters : 1,000 mL => 1,000 / 1000 => 1 L

Number of moles of solution :

number of moles = volume x molarity

number of moles = 1 x 0.3  => 0.3 moles

Therefore:

1 mole Mg₃(PO₄)₂ ------------------- 262.86 g

0.3 moles ----------------------------- mass of Mg₃(PO₄)₂  ??

mass of Mg₃(PO₄)₂ = 0.3 x 262.86 / 1

mass of Mg(PO₄)₂ => 78.858 g

Hope this helps!

Answer: frfg6

Explanation: 655tyyt

Answer:

Approximately [tex]19.1\; \rm g[/tex].

Explanation:

The unit of concentration in this question is "[tex]\rm M[/tex]". That's equivalent to "[tex]\rm mol \cdot L^{-1}[/tex]" (moles per liter.) In other words:

[tex]c(\mathrm{MgSO_4}) = 2.68\; \rm M = 2.68\; \rm mol \cdot L^{-1}[/tex].

However, the unit of the volume of this solution is in milliliters. Convert that unit to liters:

[tex]\displaystyle V = 59.3\; \rm mL = 59.3 \; \rm mL \times \frac{1\; \rm L}{1000\; \rm mL} = 0.0593\; \rm L[/tex].

Calculate the number of moles of [tex]\rm MgSO_4[/tex] formula units required to make this solution:

[tex]\begin{aligned}n(\rm MgSO_4) &= c \cdot V \\ &= 2.68 \; \rm mol \cdot L^{-1} \times 0.0593\; \rm L \approx 0.159\; \rm mol \end{aligned}[/tex].

Look up the relative atomic mass data of [tex]\rm Mg[/tex], [tex]\rm S[/tex], and [tex]\rm O[/tex] on a modern periodic table:

Calculate the formula mass of [tex]\rm MgSO_4[/tex] using these values:

[tex]M(\mathrm{MgSO_4}) = 24.305 + 32.06 + 4 \times 15.999 \approx 120.361\; \rm g \cdot mol^{-1}[/tex].

Using this formula mass, calculate the mass of that (approximately) [tex]0.159\; \rm mol[/tex] of [tex]\rm MgSO_4[/tex] formula units:

[tex]\begin{aligned}m(\mathrm{MgSO_4}) &= n \cdot M \\&\approx 0.159 \; \rm mol \times 120.361 \; \rm g \cdot mol^{-1} \approx 19.1\; \rm g\end{aligned}[/tex].

Therefore, the mass of [tex]\rm MgSO_4[/tex] required to make this solution would be approximately [tex]19.1\; \rm g[/tex].

Answer:

Q = 7.7 KJ

Explanation:

The complete question carries the following data:

Specific Heat Capacity of Liquid State = C(l) = 1.45 J/mol.°C

Specific Heat Capacity of Gaseous State = C(g) = 0.65 J/mol.°C

Boiling Temperature = Tb = 88.5°C

Heat of Vaporization = ΔH(vap) = 1.23 KJ/mol

Now, first we calculate the heat required (Q₁) to raise he temperature to boiling point:

Q₁ = n*C(l)*ΔT₁

where,

n = no. of moles = 5.31 mol

ΔT₁ = Temperature difference from 40°C to Tb = 88.5°C - 40°C = 48.5°C

Therefore,

Q₁ = (5.31 mol)(1.45 J/mol.°C)(48.5°C)

Q₁ = 373.4 J = 0.37 KJ

Now, we calculate the heat required (Q₂) to change its phase:

Q₂ = nΔH(vap)

Q₂ = (5.31 mol)(1.23 KJ/mol)

Q₂ = 6.53 KJ

Now, we calculate the heat required (Q₃) to raise he temperature to boiling point:

Q₃ = n*C(g)*ΔT₃

where,

n = no. of moles = 5.31 mol

ΔT₃ = Temperature difference from Tb to 113°C = 113°C - 88.5°C = 24.5°C

Therefore,

Q₃ = (5.31 mol)(0.65 J/mol.°C)(24.5°C)

Q₃ = 84.5 J = 0.08 KJ

So, the total heat required to convert 5.31 mol of this pure substance from a liquid at 40°C to a gas at 113°C is:

Q = Q₁ + Q₂ + Q₃

Q = 0.37 KJ + 6.53 KJ + 0.08 KJ

Q = 7.7 KJ

The total heat required to convert the pure substance from liquid to gas at the given temperature is 814 J.

The given parameters;

The total heat required to convert the pure substance from liquid to gas at the given temperature is calculated as follows;

[tex]Q = nc_l \Delta \theta + nc_g \Delta \theta \\\\ \Delta \theta = (113 - 40) = 73^0 C \\\\Q = (5.31 \ mol \times 1.45 \frac{J}{mol .\ ^0C} \times 73\ ^0C) + (5.31 \ mol \times 0.65 \frac{J}{mol .\ ^0C} \times 73 \ ^0C)\\\\Q = 814 \ J[/tex]

Thus, the total heat required to convert the pure substance from liquid to gas at the given temperature is 814 J.

"Your question is not complete, it seems to be missing the following information;"

How much heat would be required to convert 5.31 mol of a pure substance from a liquid at 40.0°C to a gas at 113.0°C? (molar heat capacity of liquid, C(l) is 1.45 J/mol.⁰C and molar heat capacity of gas, C(g) is 0.65 J/mol.⁰C).

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Answer:

The correct answer is "[tex]\frac{0.65}{V} \ percent[/tex]".

Explanation:

The given values are:

[tex]M_r=0.130 \ g[/tex]

[tex]M_o=20 \ g/L\times V(L)[/tex]

     [tex]=20 \ V[/tex]

As we know,

⇒ [tex]Recovery \ percent=\frac{Amount \ of \ substance \ recovered}{Amount \ of \ substance \ originally \ taken}\times 100[/tex]

On substituting the given values, we get

                                [tex]=\frac{0.130}{20 \ V}\times 100[/tex]

                                [tex]=\frac{0.65}{V} \ percent[/tex]

Note: percent = %

Answer:

d

Explanation:

Answer:

Its d

Explanation:

Ik you already know this, I just wanted the points tbh

Answer:

The number of energy levels increases as you move down a group as the number of electrons increases. Each subsequent energy level is further from the nucleus than the last. ... The outermost electrons are repelled by the inner shell electrons (Screening effect) and hence, the atomic size increases.

Explanation:Increase in atomic size

Answer:

Blood

Explanation:

This flows through the body so it gives it all over.

Answer:

Explanation:

Potential energy

Answer:

Explanation:

Net force F = 1800 N

acceleration a = 1.5 m /s²

mass = m

mass = force / acceleration

= 1800 / 1.5

m = 1200 kg

The mass of the vehicle to the nearest kilogram is 1200 Kg

The force acting on an object is defined by the following equation

Force (F) = mass (m) × Acceleration (a)

F = ma

With the above formula, we can obtain the mass of the vehicle as follow:

Force (F) = 1800 N

Acceleration (a) = 1.5 m/s²

[tex]m = \frac{F}{a} \\ \\ m = \frac{1800}{1.5} \\ \\ m = 1200 \: Kg[/tex]

Therefore, the mass of the vehicle is 1200 Kg

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Answer: how do we answer when there are no options??

Explanation:

Answer:

Chemical

Explanation:

Cause it is

Answer:

it indicates, how many atoms or ions of each type are combined in the simplest unit.

Answer:

Atomic size is the distance from the nucleus to the valence shell where the valence electrons are located. The separation that occurs because electrons have the same charge. The number of protons in the nucleus. The core electrons in an atom interfere with the attraction of the nucleus for the outermost electrons.

Explanation:

That would be B I believe, but please correct me if I'm wrong.

Answer:129.839 g/mol

Explanation:

Answer:

the answer is D. N

AP3X

According to electronic configuration, there are 3 electrons in the 2p sublevel ,hence the correct option is D.

Electronic configuration is defined as the distribution of electrons that are present in an atom or molecule in  an atomic or molecular orbitals.It describes how each electron moves independently in an orbital.

Knowledge of electronic configuration is important for understanding the structure of periodic table. It helps in understanding the chemical properties of elements.

Elements undergo chemical reactions so as to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in  their ground state and hence are said to be stable.

Thus, the correct option is D.

Learn more about electronic configuration,here:

https://brainly.com/question/29184975

#SPJ4

Answer:

opposite

Explanation:

Answer:

opposite

Explanation:

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Answer:

it's answer is

element of an atom ✌️

Answer:

They can’t have more than 8 valence electrons.

Explanation:

Answer:

The answer is true

Explanation: Because The law of multiple proportions states that when two elements react to form more than one compound, a fixed mass of one element will react with masses of the other element in a ratio of small, whole numbers.

Answer:

1. a

Explanation:

2. c

Answer:

1 is A number two is C

Answer:

Mechanical

Explanation:

chemical

Explanation:

I took test 2020

Answer:

We can see that the atomic radius decreases across every row.

Explanation:

I will comment more below.

The elements that represent the highest points on the graph are all elements of group 1 and occur at the head of the period to which they belong.

The periodic table is an arrangement of elements in groups and periods. The elements in the same group have the same number of valence electrons while the elements in the same period have the same number of shells.

Looking at the graph, we can see that the high points in the graph all correspond to the group 1 elements; sodium, potassium, rubidium and cesium.The have the highest atomic radii in the period. Atomic radii increases down the group but decreases across the period. Remember that these elements are at the head of the period to which they belong hence they have the highest atomic radii.

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