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2 years ago

How many neutrons does element X have if its atomic number is 20 and its mass number is 82?

1 answer:

6 0

Protons = Atomic number
Protons + Neutrons = Mass Number
Protons = 20
Neutrons = Atomic number - Mass number
Neutrons = 82 - 20 = 62

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Determine the identity of a cube of metal that measures 1.2 cm on each side and has a mass of 15.4g.

FromTheMoon [43]

Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions.
density 15.4 grams per 1.2³ cm³ ≅ 8.9 grams per cm³
Find the metal that has a density of approximately 8.9 g/cm³

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2 years ago

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What are the spectator ions in this reaction

Lady_Fox [76]

sodium ions and chloride ions

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3 years ago

Suppose that 0.1000 mole each of H2and I2are placed in a 1.000-L flask, stoppered, and the mixture is heated to 425oC. At equili

Katen [24]

Answer: The value of equilibrium constant for the given reaction is 56.61

Explanation:

We are given:

Initial moles of iodine gas = 0.100 moles

Initial moles of hydrogen gas = 0.100 moles

Volume of container = 1.00 L

Molarity of the solution is calculated by the equation:

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

$\text{Molarity of iodine gas}=\frac{0.1mol}{1L}=0.1M$

$\text{Molarity of hydrogen gas}=\frac{0.1mol}{1L}=0.1M$

Equilibrium concentration of iodine gas = 0.0210 M

The chemical equation for the reaction of iodine gas and hydrogen gas follows:

$H_2+I_2\rightleftharpoons 2HI$

Initial: 0.1 0.1

At eqllm: 0.1-x 0.1-x 2x

Evaluating the value of 'x'

$\Rightarrow (0.1-x)=0.0210\\\\\Rightarrow x=0.079M$

The expression of $K_c$ for above equation follows:

$K_c=\frac{[HI]^2}{[H_2][I_2]}$

$[HI]_{eq}=2x=(2\times 0.079)=0.158M$

$[H_2]_{eq}=(0.1-x)=(0.1-0.079)=0.0210M$

$[I_2]_{eq}=0.0210M$

Putting values in above expression, we get:

$K_c=\frac{(0.158)^2}{0.0210\times 0.0210}\\\\K_c=56.61$

Hence, the value of equilibrium constant for the given reaction is 56.61

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3 years ago

Are metallic bonds are found in compounds

Ratling [72]

Answer:

Explanation:

Yes :)

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2 years ago

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Which describes the composition of carbohydrates?

UkoKoshka [18]

Answer: Carbohydrates (carbo- = “carbon”; hydrate = “water”) contain the elements carbon, hydrogen, and oxygen, and only those elements with a few exceptions. The ratio of carbon to hydrogen to oxygen in carbohydrate molecules is 1:2:1.

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2 years ago