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2 years ago

An arrow is fired at a target on a high wal. How does the energy change between the moment the arrow is fired and the

Chemistry

2 answers:

uranmaximum [27]2 years ago

6 0

Answer:

The kinetic energy decreases as potential energy increases.

Explanation:

Phoenix [80]2 years ago

4 0

Answer: answer is C on Edge

Explanation:

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What types of compounds do not dissolve in water?

Nataliya [291]

Oil doesn't dissolve in water, which could be your answer.

8 0

3 years ago

The half-life of cesium-137 is 30 years. Suppose we have a 180 mg sample. Find the mass that remains after t years. Let y(t) be

Stels [109]

Explanation:

1) Initial mass of the Cesium-137= $N_o$ = 180 mg

Mass of Cesium after time t = N

Formula used :

$N=N_o\times e^{-\lambda t}\\\\\lambda =\frac{0.693}{t_{\frac{1}{2}}}$

Half life of the cesium-137 = $t_{1/2}=30 years[p/tex]where,
[tex]N_o$ = initial mass of isotope

N = mass of the parent isotope left after the time, (t)

$t_{\frac{1}{2}}$ = half life of the isotope

$\lambda$ = rate constant

$N=N_o\times e^{-(\frac{0.693}{t_{1/2}})\times t}$

Now put all the given values in this formula, we get

$N=180mg\times e^{-\frac{0.693}{30 years}\times t}$

Mass that remains after t years.

$N=180 mg\times e^{0.0231 year^{-1}\times t}$

Therefore, the parent isotope remain after one half life will be, 100 grams.

t = 70 years

$N_o=180 mg$

$t_{1/2}= 30 yeras$

$N=180mg\times e^{-\frac{0.693}{30 years}\times 70 years}$

N = 35.73 mg

35.73 mg of cesium-137 will remain after 70 years.

$N_o=180 mg$

$t_{1/2}= 30 yeras$

N = 1 mg

t = ?

$1 mg =180mg\times e^{-\frac{0.693}{30 years}\times t}$

$\frac{-30 year}{0.693}\times \ln \frac{1 mg}{180 mg}=t$

t = 224.80 years ≈ 225 years

After 225 years only 1 mg of cesium-137 will remain.

7 0

3 years ago

A molecular covalent substance (such as co2) has a low melting point because the covalent bonds that hold the molecules together

Leona [35]

A molecular covalent substance (such as co2) has a low melting point because the covalent bonds that hold the molecules together are weak and do not require much energy to break:- False.

What are covalent bonds ?

An electron transfer that leads to the formation of electron pairs between atoms is known as a covalent bond. When atoms share electrons, a stable balance of the repulsive and attractive forces among them is known as covalent bonding. These electron pairs are also known as bonds or shared pairs.

It is a molecular compound, which is a mixture of at least two atoms—the smallest building blocks of matter—joined by a covalent bond. These atoms are joined by a covalent bond, which is formed when electrons are shared.

Learn more about covalent bond here:-

brainly.com/question/19382448

#SPJ4

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1 year ago

Hello, please help me answer this it’s due tonight!

77julia77 [94]

Answer:

Explanation:

I think you should desigh a home. (you might say well thats obvi) I'm not done!

OK anyway desigh a house and think about ways to keep it warm. LIke a heater of fire place. ALso think about how you would get oxegen and air to live, since your on mars. Also use information about mars to help you!

- Hope it helps!

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3 years ago

Question 12 of 25

Tomtit [17]

Answer:

Explanation:

All atoms are divisible

6 0

2 years ago