Answer:
= 72900 years
Explanation:
- The half-life is the time taken by a radioactive material to decay by half the original amount.
- The half-life of plutonium-239 is 24300 years which means it takes 24300 years to decay by half the original amount.
To calculate the time taken for a mass of 8 kg to decay to 1 kg we use;
New mass = Original mass x (1/2) ^n, where n is the number of half-lives
Therefore;
1 kg = 8 kg × (1/2)^n
1/8 = (1/2)^n
solving for n;
n =3
Therefore;
Time = 3 × 24300 years
= 72900 years
It will, therefore, take 72900 years for 8 kg of plutonium-239 to decay to 1 kg.
So so sorry if i'm wrong but i'm pretty sure no
This question comes with four answer choices:
<span>A. H2O + H2O ⇄ 2H2 + O2
B. H2O + H2O⇄ H2O2 + H2
C. H2O + H2O ⇄ 4H+ + 2O2-
D. H2O + H2O ⇄ H3O+ + OH-
Answer: option </span><span>D. H2O + H2O ⇄ H3O+ + OH-
(the +sign next to H3O is a superscript, as well as the - sing next to OH)
Explanation:
The self-ionization of water, or autodissociation, produces the two ions H3O(+) and OH(-). The presence of ions is what explain the electrical conductivity of pure water.
</span><span>In this, one molecule of H2O loses a proton (H+) (deprotonates) to become a hydroxide ion, OH−. Then, he <span>hydrogen ion, H+</span>, immediately protonates another water molecule to form hydronium, H3O+.
</span>
Answer:
Number of moles = 2.89 mol
Explanation:
Given data:
Number of moles of sugar = ?
Mass of sugar = 990 g
Solution:
Formula:
Number of moles = mass/molar mass
Molar mass of C₁₂H₂₂O₁₁:
12× 12 + 22×1.008 + 16×11 = 342.2 g/mol
Number of moles = 990 g / 342.2 g/mol
Number of moles = 2.89 mol
