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mestny [16]
2 years ago
5

What is the half-life of Technetium-99 if a 200 gram sample decays to 50 grams in 639,000 years?

Chemistry
1 answer:
Elenna [48]2 years ago
5 0

Answer:

The half-life of Th-232 is 1.4 ∙ 10¹⁰ years.

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Define mass number
Ganezh [65]

Answer:

protons plus neutrons

Explanation:

An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.

All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons.

The sum of neutrons and protons is the mass number of an atom.

Mass number = number of protons + number of neutrons

while the number of protons or number of electrons is the atomic number of an atom.

8 0
2 years ago
A 10.0 L balloon contains helium gas at a pressure of 655 mmHg. What is the final pressure, in millimeters of mercury, if the fi
joja [24]

Answer:

474.64mmHg

Explanation:

From the question given, we obtained the following:

V1 = 10L

P1 = 655mmHg

V2 = 13.8L

P2 =?

P1V1 = P2V2

10 x 655 = P2 x 13.8

Divide both side by the coefficient P2 i.e 13.8

P2 = (10 x 655) / 13.8

P2 = 474.64mmHg

Therefore, the new pressure will be 474.64mmHg

7 0
3 years ago
A system does 591 kJ of work and loses 256 kJ of heat to the surroundings.
Mars2501 [29]

Answer:

-847kj

Explanation:

Delta E= -256+-591

5 0
2 years ago
Using the accepted value for the volume of 1 gram of water at the temperature of the room that you reported above, what is the a
inessss [21]

Write procedural steps that allow you to demonstrate the sun's role in the water cycle using common material - for each explain what you are modeling and how the materials you have chosen represent nature.

Using the accepted value for the volume of 1 gram of water at the temperature of the room that you reported above, what is the accepted value for the density of water

3 0
3 years ago
Which waves can travel through empty space?
bagirrra123 [75]

Answer:

light waves a

Explanation:

because there's all kinds of different light in space if you think about it like the bright stars or the bright moon it's kind of like light it just makes sense when it's traveling for space water waves obviously it's not possible that travels through the air or like on a beach sound waves you can't really cure much in space and mechanical waves is pretty much the action of an object or something like that kind of it's pretty much happens on Earth but light waves happen for like asteroids or shooting stars a comments it happens all the time for space so it makes just perfect sense

3 0
2 years ago
Read 2 more answers
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