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3 years ago

1. Explain how and why stars appear to move through the sky throughout the night. Then, explain why Polaris does not move.

Chemistry

1 answer:

Bas_tet [7]3 years ago

3 0

Polaris the north star is very bright and it doesn’t move

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How many molecules are in 68.0 g of H2S

Kryger [21]

The correct answer is 12.044 × 10²³ molecules.

The molecular mass of H₂S is 34 gram per mole.

Number of moles is determined by using the formula,

Number of moles = mass/molecular mass

Given mass is 68 grams, so no of moles will be,

68/34 = 2 moles

1 mole comprises 6.022 × 10²³ molecules, therefore, 2 moles will comprise = 6.022 × 10²³ × 2

= 12.044 × 10²³ molecules.

3 0

3 years ago

Select the correct structure that

Leni [432]

Answer:

Explanation:

its b

8 0

3 years ago

In the spring of 1984, concern arose over the presence of ethylene dibromide, or EDB, in grains and cereals. EDB has the molecul

Lady bird [3.3K]

869.6 × 10¹⁴ molecules of EDB

Explanation:

We have 1.9 lb of flour with a EDB concentration of 31.5 ppb.

We need to transform lb in grams.

1 lb = 453.6 grams

1.9 lb = (1.9 × 453.6) / 1 = 861.8 grams

Now we determine the number of molecules of EDB in the sample by devise the following reasoning:

if we have 31.5 × 10⁻⁹ g of EDB in 1 g of sample

then we have X g of EDB in 861.8 g of sample

X = (31.5 × 10⁻⁹ × 861.8) / 1 = 27146.7 × 10⁻⁹ g of EDB

Molecular mass of EDB (C₂H₄Br₂) = 188 g/mole

Taking in account that 1 mole of any substance contains 6.022 × 10²³ (Avogadro’s number) molecules we devise the following reasoning:

if 188 g of EDB contains 6.022 × 10²³ molecules

then 27146.7 × 10⁻⁹ g of EDB contains Y molecules

Y = (27146.7 × 10⁻⁹ × 6.022 × 10²³) / 188 = 869.6 × 10¹⁴ molecules of EDB

Learn more:

about Avogadro’s number

brainly.com/question/1445383

#learnwithBrainly

8 0

3 years ago

Read 2 more answers

A ground water tank has its height 2m. Calculate the pressure at its bottom when it is completely filled with water.

Law Incorporation [45]

The pressure at the bottom : 19600 N/m²

<h3>Further explanation</h3>

Given

A ground water tank has its height 2m

Required

The pressure at its bottom

Solution

Hydrostatic pressure is the pressure caused by the weight of a liquid.

The weight of a liquid is affected by the force of gravity.

The hydrostatic pressure of a liquid can be formulated:

$\large{\boxed{\bold {P_h ~ = ~ \rho.g.h}}$

Ph = hydrostatic pressure (N / m², Pa)

ρ = density of liquid (kg / m³)

g = acceleration due to gravity (m / s²)

h = height / depth of liquid surface (m)

ρ = density of water (kg / m³) = 1000

g = acceleration due to gravity = 9.8 m/ sec²

The pressure

$\tt P=1000\times 9.8\times 2=19600~N/m^2$

6 0

3 years ago

What is another name for energy lost through heat and sound?

Arturiano [62]

Answer:Figure 1. Energy losses in an incandescent light bulb are very large; most of the input energy is lost in the form of heat energy. This means that when energy is converted to a different form, some of the input energy is turned into a highly disordered form of energy, like heat. ...

Explanation:

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3 years ago

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