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2 years ago

What is the mass number of the isotope lithium-7??

Physics

2 answers:

svp [43]2 years ago

8 0

Explanation:

Mass number is the sum of total number of protons and total number of neutrons present in an atom.

For example, a neutral atom of lithium has mass number 7 and atomic number 3.

Atomic number means the total number of protons present in an atom.

So, isotope of lithium-7 will have 3 protons and 4 neutrons. Thus, mass number of lithium-7 will be 3 + 4 = 7.

FromTheMoon [43]2 years ago

5 0

Lithium-7 is by far the most-common isotope, making up about 92.5 percent of all natural lithium. A lithium-7 atom contains three protons, four neutrons, and three electrons.

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Illustrate a body of mass 5.0kg pulled by horizontal force F . if the body accelerates 2.0ms² and experience a frictional force

Natasha2012 [34]

Explanation:

a. Net force is mass times acceleration (Newton's second law).

∑F = ma

∑F = (5.0 kg) (2.0 m/s²)

∑F = 10 N

b. The net force is the sum of the individual forces.

10 N = F − 5 N

F = 15 N

c. Friction force here is mgμ.

mgμ = 5 N

(5.0 kg) (10 m/s) μ = 5 N

μ = 0.1

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2 years ago

Complex carbohydrates, such as _____ and _____, provide the body with long-lasting energy.

Sauron [17]

complex carbohydrates, such as starches and fiber, provide the body with long-lasting energy.

Hope this helps!

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2 years ago

Read 2 more answers

A protein molecule in an electrophoresis gel has a negative charge. The exact charge depends on the pH of the solution, but 30 e

Reika [66]

Answer:

7.401 * 10^(-15) N

Explanation:

30 electrons will have a charge:

30 * -1.6022 * 10^(-19) C

= - 4.806 * 10^(-18) C

The relationship between electric field and electric force is:

E = F/q

This means that force, F, is

|F| = |E|*|q|

|F| = |1540| * |-4.806 * 10^(-18)|

|F| = |-7401.24 * 10^(-18)|

|F| = 7.401 * 10^(-15) N

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3 years ago

What percentage of energy is available to organisms at each level of an energy pyramid?

Snowcat [4.5K]

The percentage of energy available to each organism is always 10 percent .

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3 years ago

A truck traveling at a velocity of 33m/s comes to a halt by decelerating at 11m/s^2. How far does the truck travel in the proces

snow_lady [41]

Answer:

The truck was moving 16.5 m/s during the time it took to stop, which was 3 seconds.

Initial velocity = 33 m/s

Final velocity = 0 m/s

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Explanation:

First, how long does it take the truck to come to a complete stop?

( 33 m/s ) / ( 11 m / s^2 ) = 3 seconds

Then we can look at the average velocity between when the truck started decelerating and when it came to a complete stop. Because the deceleration is constant (always 11m/s^2) we can use this trick.

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2 years ago