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3 years ago

Stars form inside giant clouds of gas and dust. What are these giant clouds of gas and dust called?

Chemistry

2 answers:

Nataliya [291]3 years ago

7 0

Answer:

Explanation:

I'd put D for my answer

lesya [120]3 years ago

3 0

They are called nebulas

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Calculate the specific heat capacity of a piece of ice if 1.30 kg of the wood absorbs 6.75×104 joules of heat, and its temperatu

Gre4nikov [31]

Answer:

$c=2.0769\ \frac{J}{g\ \textdegree C}$

Explanation:

-Specific heat capacity is given by the formula:

$q=mc\bigtriangleup T$

Where:

$q$ is the heat gained or loosed by the substance

$m$ is the mass of the substance

$c$ is the specific heat of the substance

$\bigtriangleup T$ is the change in temperature

#We make c the subject of the formula and substitute to solve for it:

$q=mc\bigtriangleup T\\\\c=\frac{q}{m\bigtriangleup T}\\\\\bigtriangleup T=(57-32)\textdegree C=25\textdegree C\\\\\therefore c=\frac{6.75\times 10^4J}{1.3\times 1000\ g\times 25\textdegree C}\\\\=2.0769 \ \frac{J}{g\ \textdegree C}$

Hence, the specific heat capacity of the ice is $2.0769 \frac{J}{g\ \textdegree C}$

8 0

3 years ago

in Analytical chemistry laboratory. Nickle(ppm)in water sample estimated by two different students was as ,student 1 (25 24 24 2

frosja888 [35]

Answer:

Answers are in the explanation

Explanation:

Precision and accuracy are both statistical concepts. Precision is about how close are the measured values to each other. Accuracy is closeness of the measured values to a specific value or reference value.

There are many ways to calculate precision and accuracy, one is stimating precision as Relative Uncertainty and accuracy as Relative Error.

Formulas are:

Relative Uncertainty: Standard desviation / Measured value.

Relative Error: Measured Value - Expected Value / Expected value

Measured value is the aveage of the values.

For student 1:

Mean = 25

Standard desviation = 1.5275

Relative Uncertainty: 1.5275 / 25

Relative Uncertainty: 0.061

Relative Error: 25 - 20 / 20

Relative Error: 0.25

For student 2:

Mean = 24.5

Standard desviation = 0.5477

Relative Uncertainty: 0.5477 / 24.5

Relative Uncertainty: 0.02

Relative Error: 24.5 - 20 / 20

Relative Error: 0.225

As the student 2 has a low Relative error and uncertainty, you can say student 2 is more accurate and precise

6 0

3 years ago

Méthode pour sépare l'eau et vermiculite !

wolverine [178]

Answer:

Filtración

Explanation:

Cuando se filtra una mezcla de arena y agua, la vermiculita se queda en el papel de filtro y el agua gotea. Como un filtro de café.

8 0

2 years ago

How many hours are in 188 years

AURORKA [14]

Answer: about 1,705,536 hrs

24 hrs = 1 day

189 hrs = 1 week

756 = 1 month

9072 = 1 yr

1,705,536 = 188 yrs

Explanation:

Trust Milky. Milky smart

7 0

3 years ago

Describe the properties of alkali metals. Based on their electronic arrangement, explain whether they exist alone in nature.

bearhunter [10]

Answer:

- They are highly reactive metals

- They have low electro negativity

- They have low ionization energy

- They don't exist alone in nature

- They have low densities

Explanation:

Alkali metals are the elements in group 1 of the periodic table. They include Sodium, Lithium, Potassium e.t.c.

Due to the fact they have one atom in their outermost shell, they are very unstable because they easily react with other elements and are therefore don't exist alone in nature but combined with other elements for this same reason.

Since alkali metals don't easily attract other elements due to it's lone pair in the outer most shell, it can be said to have low electro negativity.

Also, they don't need energy to discharge their electrons since they are highly reactive due to their lone pair in the outermost shell and so we say they have low ionization energy.

Due to this reason, they also have low densities.

7 0

2 years ago