A light or optical microscope most commonly uused is a

Electrons orbit the nucleus like planets around the sun. true or false?

gogolik [260]

Answer: true

Explanation: Electrons orbit the nucleus of an atom the way that planets revolve around the Sun. The electrons are like the planets in the solar system. The sun is like the nucleus in the solar system. The answer to the question is true.

7 0

2 years ago

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During the phase change from solid ice to liquid water, which bonds/forces are being weakened?

vampirchik [111]

I think Intramolecular forces are being weakened

5 0

2 years ago

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3. A compound consists of 91.63 grams of carbon, 7.69 grams of hydrogen and 40.81 grams of

Vikentia [17]

Answer:

Molecular formula = C₁₂H₁₂O₄

Empirical formula is C₃H₃O.

Explanation:

Given data:

Mass of C = 91.63 g

Mass of H = 7.69 g

Mass pf O = 40.81 g

Molar mass of compound = 220 g/mol

Empirical formula = ?

Molecular formula = ?

Solution:

Number of gram atoms of H = 7.69 / 1.01 = 7.61

Number of gram atoms of O = 40.81 / 16 = 2.55

Number of gram atoms of C = 91.63 / 12 = 7.64

Atomic ratio:

C : H : O

7.64/2.55 : 7.61 /2.55 : 2.55/2.55

3 : 3 : 1

C : H : O = 3 : 3 : 1

Empirical formula is C₃H₃O.

Molecular formula:

Molecular formula = n (empirical formula)

n = molar mass of compound / empirical formula mass

Empirical formula mass = 3×12+ 3×1.01 +16 = 55.03

n = 220 / 55.03

n = 4

Molecular formula = 4 (empirical formula)

Molecular formula = 4 (C₃H₃O)

Molecular formula = C₁₂H₁₂O₄

8 0

3 years ago

Humans affect the levels of air pollution by using natural resources and

Radda [10]

Chemicals that’s and ghebreziqbiher

5 0

3 years ago

A sample of gallium Bromide GaBr2,weighing 0.165 g was dissolved in water and treated with silver nitrate AgNO3, and resulting t

tresset_1 [31]

Answer: The percent gallium in gallium bromide is 30.30 %.

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

Given mass of gallium bromide = 0.165 g

Molar mass of titanium gallium bromide = 229.53 g/mol

Putting values in equation 1, we get:

$\text{Moles of gallium bromide}=\frac{0.165g}{229.53g/mol}=0.00072mol$

The chemical equation for the reaction of gallium bromide and silver nitrate follows:

$GaBr_2+2AgNO_3\rightarrow 2AgBr(s)+Ga(NO_3)_2$

By Stoichiometry of the reaction:

1 moles of gallium bromide produces 1 mole of gallium nitrate

So, 0.00072 moles of gallium bromide will produce = $\frac{1}{1}\times 0.00072=0.00072moles$ of gallium nitrate

Now, calculating the mass of gallium nitrate from equation 1, we get:

Molar mass of gallium nitrate = 193.73 g/mol

Moles of gallium nitrate = 0.00072 moles

Putting values in equation 1, we get:

$0.00072mol=\frac{\text{Mass of gallium nitrate}}{193.73g/mol}\\\\\text{Mass of gallium nitrate}=0.139g$

Calculating the mass of gallium in the reaction, we use unitary method:

In 1 mole of gallium nitrate, 1 mole of gallium atom is present.

In 193.73 grams of gallium nitrate, 69.72 g of gallium atom is present.

So, in 0.139 grams of gallium nitrate, the mass of gallium present will be = $\frac{69.72}{193.73}\times 0.139=g$

To calculate the percentage composition of gallium in gallium bromide, we use the equation:

$\%\text{ composition of gallium}=\frac{\text{Mass of gallium}}{\text{Mass of gallium bromide}}\times 100$

Mass of gallium bromide = 0.165 g

Mass of gallium = 0.050 g

Putting values in above equation, we get:

$\%\text{ composition of gallium}=\frac{0.050g}{0.165g}\times 100=30.30\%$

Hence, the percent gallium in gallium bromide is 30.30 %.

3 0

3 years ago