Answer: (E) 300 bq
Explanation:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
Radioactive decay process is a type of process in which a less stable nuclei decomposes to a stable nuclei by releasing some radiations or particles like alpha, beta particles or gamma-radiations. The radioactive decay follows first order kinetics.
Half life is represented by 
Half life of Thallium-208 = 3.053 min
Thus after 9 minutes , three half lives will be passed, after ist half life, the activity would be reduced to half of original i.e. 
, after second half life, the activity would be reduced to half of 1200 i.e. 
, and after third half life, the activity would be reduced to half of 600 i.e. 
,
Thus the activity 9 minutes later is 300 bq.
I believe it’s a positive charge
Since water molecules are polar. Unequal sharing of electrons between the elements that make it. The hydrogen atoms would experience a slight partial positive charge as the electron density is more close to the oxygen atom making it partially negative.
Answer:
A) 8.00 mol NH₃
B) 137 g NH₃
C) 2.30 g H₂
D) 1.53 x 10²⁰ molecules NH₃
Explanation:
Let us consider the balanced equation:
N₂(g) + 3 H₂(g) ⇄ 2 NH₃(g)
Part A
3 moles of H₂ form 2 moles of NH₃. So, for 12.0 moles of H₂:
Part B:
1 mole of N₂ forms 2 moles of NH₃. And each mole of NH₃ has a mass of 17.0 g (molar mass). So, for 4.04 moles of N₂:
Part C:
According to the <em>balanced equation</em> 6.00 g of H₂ form 34.0 g of NH₃. So, for 13.02g of NH₃:
Part D:
6.00 g of H₂ form 2 moles of NH₃. An each mole of NH₃ has 6.02 x 10²³ molecules of NH₃ (Avogadro number). So, for 7.62×10⁻⁴ g of H₂:
Sodium hydroxide solution and hydrogen gas are produced from the reaction of water and sodium.
<h2>Reaction of sodium and water</h2>
We observe bubbles coming out of the water when the sodium reacts with the water because of the formation of hydrogen gas which is insoluble in water so it moves into the atmosphere.
<h3>Products of the reaction</h3>
Sodium metal reacts rapidly with water to form sodium hydroxide (NaOH) solution and hydrogen gas (H2). This chemical reaction is exothermic because huge amount of heat is release from the solution so we can conclude that sodium hydroxide solution and hydrogen gas are produced from the reaction of water and sodium.
Learn more about chemical reaction here: brainly.com/question/26018275
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