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Nesterboy [21]
3 years ago
14

How long does it take for 87.5 % of each isotope to decay?

Chemistry
1 answer:
Zolol [24]3 years ago
7 0

Answer:

Kr-73 = 23.625 sec

Kr-74 = 10.0625 minutes (603.75 seconds)

Kr-76 = 12.95 hours (777 minutes)

Kr-81 = 1.8375 * 10^6 years

Explanation:

What you do is multiply each of those amounts by 7/8.

27 * 7/8 = 189/8 = 23.625

23/2 * 7/8 = 161/16 = 10.0625

74/5 * 7/8 = 518/40 = 259/20 = 12.95

210000 * 7/8 = 1470000/8 = 183750 = 1.8375 * 10^6

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Shtirlitz [24]
The number of molecules decrease
8 0
3 years ago
What is the difference between heterozygous and homozygous?
Yuri [45]

we can differentiate a heterozygous individual from a homozygote by analyzing their alleles. If the alleles in the homologous chromosomes are the same, we say that it is a homozygote. If the alleles are different, the individual is heterozygous.

5 0
4 years ago
Sulfuric acid reacts with aluminum hydroxide by double replacement. if 34 g of sulfuric acid react with 33 g of aluminum hydroxi
Lina20 [59]
Answer is: sulfuric acid is the limiting reactant.
Chemical reaction: 3H₂SO₄ + 2Al(OH)₃ → Al₂(SO₄)₃ + 6H₂O.
m(H₂SO₄) = 34 g.
n(H₂SO₄) = m(H₂SO₄) ÷ M(H₂SO₄).
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n(H₂SO₄) = 0,346 mol.
m(Al(OH)₃) = 33 g.
n(Al(OH)₃) = 33 g ÷ 78 g/mol.
n(Al(OH)₃) = 0,423 mol.
From chemical reaction: n(H₂SO₄) : n(Al(OH)₃) = 3 : 2.

4 0
4 years ago
For the following electrochemical reaction: Al3+(aq) + 3e -> Al(s) Eº = -1.66 V E° = 2.87 F2(g) + 2e -> 2F (aq) Calculate
makvit [3.9K]

<u>Answer:</u> The standard electrode potential of the cell is 4.53 V.

<u>Explanation:</u>

We are given:

E^o_{(F_2/F^-)}=2.87V\\E^o_{(Al^{3+}/Al)}=-1.66V

The substance having highest positive E^o potential will always get reduced and will undergo reduction reaction. Here, fluorine will undergo reduction reaction will get reduced.

Aluminium will undergo oxidation reaction and will get oxidized.

Substance getting oxidized always act as anode and the one getting reduced always act as cathode.

To calculate the E^o_{cell} of the reaction, we use the equation:

E^o_{cell}=E^o_{cathode}-E^o_{anode}

E^o_{cell}=2.87-(-1.66)=4.53V

Hence, the standard electrode potential of the cell is 4.53 V.

6 0
3 years ago
What mineral is the hardest known substance in nature?
shusha [124]
The mineral that is the hardest known substance in nature is a diamond. 
Hope this helps. 



3 0
3 years ago
Read 2 more answers
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