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Why does the same side of the moon always face earth? A. The rotational period of earth is the same as that of the moon B. The r

mixer [17]

Answer: A. the rotational period of the earth is the same as that of the moon

3 0

3 years ago

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Isotope Atomic Mass (amu) Percent Abundance

exis [7]

Answer:

The average atomic mass is closer to Si- 28 because this isotope is present in more percentage in the sample.

Explanation:

Given data:

Atomic mass of silicon= ?

Percent abundance of Si-28 = 92.21%

Atomic mass of Si-28 = 27.98 amu

Percent abundance of Si-29 = 4.70%

Atomic mass of Si-29 = 28.98 amu

Percent abundance of Si-30 = 3.09%

Atomic mass of Si-30 = 29.97 amu

Solution:

Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass)+(abundance of 2nd isotope × its atomic mass) / 100

Average atomic mass = (92.21×27.98)+(4.70×28.98)+(3.09×29.97) /100

Average atomic mass = 2580.04 +136.21+92.61 / 100

Average atomic mass = 2808.86 / 100

Average atomic mass = 28.08amu.

The average atomic mass is closer to Si- 28 because this isotope is present in more percentage in the sample.

7 0

3 years ago

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the volume of a cylindrical tin can with a top and a bottom is to be 16Ï cubic inches. if a minimum amount of tin is to be used

Hunter-Best [27]

Answer:

The required height of the tin can is given by the height at the minimum value of the surface area function of the tin can

The height of the tin can must be 4 inches

Reason:

The given information on the tin can are;

Volume of the tin can = 16·π in.³

The amount of tin to be used = Minimum amount

The height of the can in inches required

Solution;

Let h, represent the height of the can, we have;

The surface area of the can, S.A. = 2·π·r² + 2·π·r·h

The volume of the can, V = π·r²·h

Where;

r = The radius of the tin can

h = The height of the tin can

Which gives;

16·π = π·r²·h

16 = r²·h

Which gives;

When the minimum amount of tin is used, we have;

Therefore;

4·π·(r³ - 8) = r² × 0

r³ = 8

r = 2

The radius of the tin can, r = 2 inches

The

The height of the tin can, h = 4 inches

Learn more here:

brainly.com/question/14316282

Explanation:

8 0

3 years ago

Fred mixes a solution using two types of solutions: 0.60 liters containing 10% alcohol and 0.40 liters containing 35% alcohol. W

insens350 [35]

The alcohol concentration of the mixed solution is 20%

Simplification :

Based on the given condition, formulate :

35% ×0.40 + 0.6 ×10% ÷{ 0.4+0.6}

Calculate the product : $\frac{0.14+0.06}{0.4 + 0.6}$

Calculate the sum or difference : $\frac{0.2}{1}$

Any fraction with denominator 1 is equal to numerator : 0.2

Multiply a number to both numerator, denominator : 0.2 × $\frac{100}{100}$

Calculate the product or quotient : $\frac{20}{100}$

A fraction with denominator equals to 100 to a percentage 20%.

How do you find the concentration of a mixed solution?

In general when your are mixing two different concentrations together first calculate number of moles for each solution (n=CV ,V-in liter) then add them together it will be total moles,then concentration of mixture will be = total moles / total volume(liter).

Learn more about concentration of alcohol :

brainly.com/question/13220698

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5 0

2 years ago

Which process takes place in both plant and animal cells?

matrenka [14]

The answer is Cellular respiration because it occurs in the cytoplasm of both plants and animals.

4 0

3 years ago

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