There are 137 atoms in this molecule. C55 + H72 = 127. 127 + Mg (one atom of magnesium = 128. 128 + N4 = 132. 132 + O5 = 137.
The half life of carbon-14 is 5700 years. (Half life is the time taken by a radioactive isotope to decay by half of its original mass).
Let A₀ be the initial amount of carbon-14 that is found in living matter (t=0 years), to determine when there was 44.5% of A₀ left.
44.5 = 100 × (1/2)^n, where n is the number of half lives
0.5^n = 0.445
n = log 0.445/log 0.5
n = 1.168
But 1 half life is 5700 years
Therefore, the number of years will be 5700 × 1.168 = 6658.299725 years
≈ 6658.30 years
Answer:
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Uranus. Its axis is tilted to almost 90 degrees.
Answer:
The last option:
- NH₃ (aq) + H⁺ (aq) → NH₄⁺ (aq)
Explanation:
1) Word equation
- Aqueous ammonia + nitric acid → aqueous ammonium nitrate
2) Chemical (molecular) equation
- NH₃ (aq) + HNO₃ (aq) → NH₄ NO₃
3) Ionization reactions
Write the dissociation of the soluble ionic compounds:
4) Total ionic equation:
- NH₃ (aq) + H⁺ (aq) + NO₃⁻ (aq) → NH₄⁺ (aq) + NO₃⁻ (aq)
5) Net ionic equation
You must cancel the spectator ions, which are those ions that are repeated in both reactant and product sides, i.e. NO₃⁻. They are name spectator because they do not participate (change) during the reaction.
- NH₃ (aq) + H⁺ (aq) → NH₄⁺ (aq)
And that is the last choice of the list.
