A mystery element "X” has two stable isotopes X-50 which occurs 40% of the time
and X-60 which occurs 60% of the time. What is the average mass of element "X"?

A-50 amu
B-54 amu
C-56 amu
D-60 amu

Answer:

1. a

Explanation:

2. c

Answer:

1 is A number two is C

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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Answer:

V = 10.12 mL

Explanation:

Given that,

Density, d = 0.79 g/mL

Mass, m = 8 g

We need to find the volume of the object. Density is equal to the mass per unit volume. It can be given by :

[tex]d=\dfrac{m}{V}[/tex]

Where V is the volume of the object

[tex]V=\dfrac{m}{d}\\\\=\dfrac{8\ g}{0.79\ g/mL}\\\\V=10.12\ mL[/tex]

So, the volume of the object is 10.12 mL.

Answer:

the law of conversation of mass States that mass is an isolated system is neither created or destroyed by chemical reactions or physical transformations. according to the law of conversation of mass the mass of the product in a chemical reaction must equal to the mass of reactants

hope It helped you

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

Explanation:

Answer:

Mechanical

Explanation:

chemical

Explanation:

I took test 2020

Answer:

Chemical

Explanation:

Cause it is

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:

it's answer is

element of an atom ✌️

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:

They can’t have more than 8 valence electrons.

Explanation:

Answer:

d

Explanation:

Answer:

Its d

Explanation:

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

Answer:

Tendons and ligaments

Explanation:

Tendons connect the skeletal system to the muscular system by attaching muscle to bone.

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

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:

Blood

Explanation:

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

Answer:129.839 g/mol

Explanation:

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:

There was more erosion in the Colorado Rockies scenario where there was steady rain compared to the scenario in the same area where there was only a drizzle. There is more erosion because the steady rain increased the volume of the river more than the drizzle did. Because there was more water added to the river, the river flowed faster. The faster a river flows, the more sediments it transports or erodes.

Explanation:

Edge

There was greater erosion inside the Colorado Rockies situation when there was persistent rain.

Erosion is the loss of soil or rock from the Earth's crust's surface, as well as the movement of the removed material by natural forces (such as wind or water). The term "erosion" is used in its broadest sense to refer to the overall thinning and moulding of all landmasses on the surface of the planet, such as the corrosion of rock in its natural position, the vehicles and public of weathered material, as well as erosion brought on by wind action, marine, as well as glacial processes.

In contrast to the situation within the identical region where there was simply a drizzle, there was greater erosion inside the Colorado Rockies situation when there was persistent rain. Because the volume of a river was raised by the constant rain more than by the drizzle, there is more erosion. The river flowed more quickly as a result of the additional water. A river transfers or erodes more material the quicker it runs.

Therefore, there was greater erosion inside the Colorado Rockies situation when there was persistent rain.

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#SPJ2

Answer:

peer reveiw

Explanation:

Answer:

Peer review.

Explanation: Ask Edu

Answer:

Explanation:

Potential energy

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: frfg6

Explanation: 655tyyt