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3 years ago

3.what would be the best place to build an optical telescope?

1 answer:

3 0

I can help you with question 5. The first artificial satellite to orbit the Earth was called Sputnik I, launched by the (then) Soviet Union in 1957.

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Evaporación del alcohol cambio físico o químico?

Vlada [557]

Physical because you can see it evaporate have a great día

7 0

3 years ago

What is meant by the term neutral in relation to atoms?

Sonbull [250]

Answer:

it means positive and negative charges are equal.

Explanation:

An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.

All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.

when a neutral atom loses a electron positive charge is created because number of protons are positive charge becomes greater than negative charge.

X → X⁺ + e⁻

When a neutral atom accept the electron negative charge is created because negative charge is become greater than positive charge.

X + e⁻ → X⁻

3 0

3 years ago

The equilibrium constant for the reaction

Hitman42 [59]

The question is incomplete, here is the complete question:

The equilibrium constant for the reaction

N₂O₄(g)⇌2NO₂ at 2°C is Kc = 2.0

If each yellow sphere represents 1 mol of N₂O₄(g) and each gray sphere 1 mol of NO₂ which of the following 1.0 L containers represents the equilibrium mixture at 2°C?

The image is attached below.

Answer: The system which represents the equilibrium having value of $K_c=2.0$ is system (b)

Explanation:

Equilibrium constant in terms of concentration is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric ratios. It is expressed as $K_c$

For a general chemical reaction:

$aA+bB\rightarrow cC+dD$

The expression for $K_{c}$ is written as:

$K_{c}=\frac{[C]^c[D]^d}{[A]^a[B]^b}$

For the given chemical equation:

$N_2O_4(g)\rightleftharpoons 2NO_2$

The expression of $K_c$ for above equation follows:

$K_c=\frac{[NO_2]^2}{[N_2O_4]}$ .......(1)

We are given:

Volume of the container = 1.0 L

Value of $K_c$ = 2.0

Molarity of the substance is calculated by using the equation:

$\text{Molarity}=\frac{\text{Number of moles}}{\text{Volume}}$

For the given images:

For a:

Number of Gray spheres = 8 moles

Number of yellow spheres = 4 moles

Putting values in expression 1, we get:

$K_c=\frac{(8/1)^2}{(4/1)}\\\\K_c=16$

For b:

Number of Gray spheres = 4 moles

Number of yellow spheres = 8 moles

Putting values in expression 1, we get:

$K_c=\frac{(4/1)^2}{(8/1)}\\\\K_c=2$

For c:

Number of Gray spheres = 6 moles

Number of yellow spheres = 6 moles

Putting values in expression 1, we get:

$K_c=\frac{(6/1)^2}{(6/1)}\\\\K_c=6$

For d:

Number of Gray spheres = 2 moles

Number of yellow spheres = 8 moles

Putting values in expression 1, we get:

$K_c=\frac{(2/1)^2}{(8/1)}\\\\K_c=\frac{1}{2}$

Hence, the system which represents the equilibrium having value of $K_c=2.0$ is system (b)

3 0

3 years ago

An insulated container contains 0.3 kg of water at 20 degrees C. An alloy with a mass of 0.090 kg and an initial temperature of

Lorico [155]

Answer:

The specific heat of the alloy is 2.324 J/g°C

Explanation:

Step 1: Data given

Mass of water = 0.3 kg = 300 grams

Temperature of water = 20°C

Mass of alloy = 0.090 kg

Initial temperature of alloy = 55 °C

The final temperature = 25°C

The specific heat of water = 4.184 J/g°C

Step 2: Calculate the specific heat of alloy

Qlost = -Qwater

Qmetal = -Qwater

Q = m*c*ΔT

m(alloy) * c(alloy) * ΔT(alloy) = -m(water)*c(water)*ΔT(water)

⇒ mass of alloy = 90 grams

⇒ c(alloy) = the specific heat of alloy = TO BE DETERMINED

⇒ ΔT(alloy) = The change of temperature = T2 - T1 = 25-55 = -30°C

⇒ mass of water = 300 grams

⇒ c(water) = the specific heat of water = 4.184 J/g°C

⇒ ΔT(water) = The change of temperature = T2 - T1 = 25 - 20 = 5 °C

90 * c(alloy) * -30°C = -300 * 4.184 J/g°C * 5°C

c(alloy) = 2.324 J/g°C

The specific heat of the alloy is 2.324 J/g°C

3 0

3 years ago

A water molecule is made of two atoms of hydrogen and one atom of oxygen, as shown in the image. one red sphere attached to two

ira [324]

Answer:

model of water

Explanation:

5 0

3 years ago