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ASHA 777 [7]
3 years ago
11

Is Helium a compound,element, or.mixture

Chemistry
1 answer:
dusya [7]3 years ago
5 0

Answer:

element

Explanation:

we know that helium is a pure substance although helium atoms are sometimes mixed with their isotopes it is still the same element. since there is no other element combined with helium this makes it an element.

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That is false. Weight is not constant every place in the universe. Take space for example. It all depends on gravity. So, the answer is false. 
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PlEASE HELP MEEEE ASAP 50 PTS
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In the given reaction potassium metal is placed in water and when a reactive metal is placed in water, it reacts with water to form metal hydroxide and hydrogen gas, as a result, potassium hydroxide and hydrogen gas are produced in the reaction. A redox reaction is a reaction in which a substance is oxidized during the reaction whereas some other substance is reduced during the reaction, simultaneously.

The given chemical reaction is:

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8 0
3 years ago
The half life of plutonium-239 (239pu, pu-239) is 24,100 years. How much plutonium will remain after 1000 years if the initial a
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The mass of plutonium that will remain after 1000 years if the initial amount is 5 g when the half life of plutonium-239 (239pu, pu-239) is 24,100 years is 2.5 g

The equation is Mr=Mi(1/2)^n

where n is the number of half-lives

Mr is the mass remaining after n half lives

Mi is the initial mass of the sample

To find n, the number of half-lives, divide the total time 1000 by the time of the half-life(24,100)

n=1000/24100=0.0414

So Mr=5x(1/2)^1=2.5 g

The mass remaining is 2.5 g

  • The half life is the time in which the concentration of a substance decreases to half of the initial value.

Learn more about half life at:

brainly.com/question/24710827

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1 year ago
Which of the following is an example of kinetic energy?
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