Half life is the time taken by a radioactive isotope to decay by half its original mass.
The original mass is 200 g
Time taken is 60 hours
Final mass is 25 g
Therefore;
Final mass = Original mass × (1/2)^n; where n is the number of half lives.
25 = 200 (1/2)^n
1/8 = (1/2)^n
n = 3
Three half lives = 60 hours
1 half lives = 20 hours
Therefore; the half life of the radioactive nucleus is 20 hours
4Fe + 3O2 → 2Fe2O3 <or> The chemical formula for rust is Fe2O3. Rust is formed when iron reacts with oxygen in moist air. The following chemical equation represents the reaction: 4Fe + 3O2 → 2Fe2O3. Water is necessary for the oxidation reaction to occur and to facilitate transport of the electrons.
Answer:
B
Explanation:
carbon 12 is most useful to humans
Those tails are called hydrophobic. You can note the etymology: hydro= water, phobi = fear, aversion, dislike.
Phospholipds' tail is a long non polar chain, made of Carbon and Hydorgens, that rejects water (a polar solvent) and is attracted to non-polar compounds (oil for example). That is why that tails can atract dirt.
Answer:
Explanation:
<u>Manganese (VII) ion (an anion) has the formula MnO₄⁻</u>. A polyatomic ion is an ion that is made up of more than one atom. For example, MnO₄⁻ and NH₄⁺. Since the ion provided in the question is an anion, the polyatomic ion that would react with it will have to be a cation (positively charged).
<u>The polyatomic cation that will react with MnO₄⁻ to form a neutral compound is NH₄⁺ (ammonium ion) to form NH₄MnO₄ (Ammonium permanganate).</u>
