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3 years ago

7

Why are some constellations visible year-round, while others appear only part of the year?

2 answers:

kherson [118]3 years ago

8 0

Circumpolar constellations stay in the sky. Because of the rotation of the Earth and its orbit around the sun, we divide the stars and constellations into 2 groups. Some stars and constellations never rise nor never set, and they are called circumpolar. Thus only some constellations are visible year- round

zalisa [80]3 years ago

6 0

Circumpolar constellations stay in the sky. Because of the rotation of the Earth and its orbit around the Sun, we divide the stars and constellations into two groups. Some stars & constellations never rise nor set, and they are called circumpolar.

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What is the molar mass of Fe2(CO3)3?

dybincka [34]

Answer:

291.7167

Explanation:

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3 years ago

What is something similar to a fossil

Flauer [41]

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4 years ago

What are fossil fuels made from

TiliK225 [7]

Answer:

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Explanation:

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3 years ago

What is the total number of joules of heat needed to change 300 g of water to

Mandarinka [93]

Answer:

6.78 × 10⁵ J

Explanation:

Step 1: Given and required data

Mass of water (m): 300 g

Latent heat of vaporization of water (ΔH°vap): 2260 J/g

Step 2: Calculate the heat (Q) required to vaporize 300 grams of water

We will use the following expression.

Q = ΔH°vap × m

Q = 2260 J/g × 300 g

Q = 6.78 × 10⁵ J

6.78 × 10⁵ Joule will be required to convert 300 g of water to steam at 100 °C.

3 0

3 years ago

For most solids at room temperature, the specific heat is determined by oscillations of the atom cores in the lattice (each osci

Cloud [144]

Answer:

The specific heat of copper is $C= 392 J/kg\cdot ^o K$

Explanation:

From the question we are told that

The amount of energy contributed by each oscillating lattice site is $E =3 kT$

The atomic mass of copper is $M = 63.6 g/mol$

The atomic mass of aluminum is $m_a = 27.0g/mol$

The specific heat of aluminum is $c_a = 900 J/kg-K$

The objective of this solution is to obtain the specific heat of copper

Now specific heat can be defined as the heat required to raise the temperature of 1 kg of a substance by $1 ^o K$

The general equation for specific heat is

$C = \frac{dU}{dT}$

Where $dT$ is the change in temperature

$dU$ is the change in internal energy

The internal energy is mathematically evaluated as

$U = 3nk_BT$

Where $k_B$ is the Boltzmann constant with a value of $1.38*10^{-23} kg \cdot m^2 /s^2 \cdot ^o K$

T is the room temperature

n is the number of atoms in a substance

Generally number of atoms in mass of an element can be obtained using the mathematical operation

$n = \frac{m}{M} * N_A$

Where $N_A$ is the Avogadro's number with a constant value of $6.022*10^{23} / mol$

M is the atomic mass of the element

m actual mass of the element

So the number of atoms in 1 kg of copper is evaluated as

$m = 1 kg = 1 kg * \frac{10000 g}{1kg } = 1000g$

The number of atom is

$n = \frac{1000}{63.6} * (6.0*0^{23})$

$= 9.46*10^{24} \ atoms$

Now substituting the equation for internal energy into the equation for specific heat

$C = \frac{d}{dT} (3 n k_B T)$

$=3nk_B$

Substituting values

$C = 3 (9.46*10^{24} )(1.38 *10^{-23})$

$C= 392 J/kg\cdot ^o K$

5 0

3 years ago