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3 years ago

Which cannot be separated into simpler substances?

Physics

2 answers:

marin [14]3 years ago

6 0

Answer:

An element is a pure substance that cannot be separated into simpler substances by chemical or physical means. There are about 117 elements.

Explanation:

Vikentia [17]3 years ago

6 0

Answer:

A pure substance

Explanation:

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A. Calculate the diffraction limit of the human eye, assuming a wide-open pupil so that your eye acts like a lens with diameter

myrzilka [38]

A. The Dawes limit tells us that the resolving power is equal to 11.6 / d, where d is the diameter of the eye’s pupil in units of centimeters. The eye's pupil can dialate to approximately 7 mm, or 0.7 cm. So 11.6 / .7 = 16.5 arc seconds, or about a quarter arc minute ~ 17 arc seconds

Although, the standard answer for what people can really see is about 1 arc minute.

B. It is considered as linear, so given a 10 meter telescope (10,000 mm):

10000 / 7 = 1428 times better for the 10 meter scope ~ 1400 times better (in 2 significant figures)

C. For a 7 cm interferometer, that is just similar to a 7 cm scope. Therefore we would expect

11.6 / 7 = 1.65 arc seconds ~ 1.7 arc seconds

This value is what we typically can get from a 7 cm scope.

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3 years ago

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Please help in finding the Total Resistence, Total Current, Req Current Center of Parallel and V40 olms

Blizzard [7]

Total Current = 2 Amps
Req total = 60 ohms
Current on EF mesh = 1/3 Amp
Current on 24 ohms resistor = 1/6 Amp

Voltage on the 40ohms resistor is lefting.

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3 years ago

Given the thermochemical equations X2+3Y2⟶2XY3ΔH1=−370 kJ X2+2Z2⟶2XZ2ΔH2=−120 kJ 2Y2+Z2⟶2Y2ZΔH3=−270 kJ Calculate the change in

Alchen [17]

Answer : The change in enthalpy of the reaction is, -310 kJ

According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.

According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.

The given main reaction is,

$4XY_3+7Z_2\rightarrow 6Y_2Z+4XZ_2$ $\Delta H=?$

The intermediate balanced chemical reaction will be,

(1) $X_2+3Y_2\rightarrow 2XY_3$ $\Delta H_1=-370kJ$

(2) $X_2+2Z_2\rightarrow 2XZ_2$ $\Delta H_2=-120kJ$

(3) $2Y_2+Z_2\rightarrow 2Y_2Z$ $\Delta H_3=-270kJ$

Now we will reverse the reaction 1 and multiply reaction 1 by 2, reaction 2 by 2 and reaction 3 by 3 then adding all the equations, we get :

(1) $4XY_3\rightarrow 2X_2+6Y_2$ $\Delta H_1=2\times (+370kJ)=740kJ$

(2) $2X_2+4Z_2\rightarrow 4XZ_2$ $\Delta H_2=2\times (-120kJ)=-240kJ$

(3) $6Y_2+3Z_2\rightarrow 6Y_2Z$ $\Delta H_3=3\times (-270kJ)=-810kJ$

The expression for enthalpy of formation of $CH_4$ will be,

$\Delta H=\Delta H_1+\Delta H_2+\Delta H_3$

$\Delta H=(+740kJ)+(-240kJ)+(-810kJ)$

$\Delta H=-310kJ$

Therefore, the change in enthalpy of the reaction is, -310 kJ

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3 years ago

Jamie is a hairstylist who works in a salon. He noticed that when many of the stylist or blow drying hair the power goes out wha

Mashcka [7]

The people are using a lot of electricity blow drying to many peoples hair so i would make a schedule so it dosent get to busy with costumers

6 0

3 years ago

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Name three types of stress that a force can cause inside an object?

Anton [14]

Answer:

Explanation:

Stress is the force applied to a rock and may cause deformation. The three main types of stress are typical of the three types of plate boundaries: compression at convergent boundaries, tension at divergent boundaries, and shear at transform boundaries.

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3 years ago