Answer:
It takes 86 days take to cover half of the lake
Explanation:
In the day #1, the amount of the algae is X,
In the day #2 is 2X
In the day #3 is 2*2*X = X*2²
...
In the day #n the amount of the algae is X*2^(n-1)
Assuming X = 1m³. In the day 87, the area infected was:
1m³*2^(87-1)
7.74x10²⁵m³ is the total area of the lake
the half of this amount is 3.87x10²⁵m³
The time transcurred is:
3.87x10²⁵m³ = 1m³*2^(n-1)
Multiplying for 5 in each side:
ln (3.87x10²⁵) = ln (2^(n-1))
58.9175 = n-1 * 0.6931
85 = n-1
86 = n
<h3>It takes 86 days take to cover half of the lake</h3>
Answer:
(a) 3:2; (b) 2:1
Explanation:
The Law of Multiple Proportions states that when two elements A and B combine to form two or more compounds, the masses of B that combine with a given mass of A are in the ratios of small whole numbers.
That is, if one compound has a ratio r₁ and the other has a ratio r₂, the ratio of the ratios r is in small whole numbers.
(a) Ammonia and hydrazine.
In ammonia, the mass ratio of H:N is r₁ = 0.2158/1
In hydrazine, the mass ratio of H:N is r₂ = 0.1439/1
The ratio of the ratios is:
(b) Nitrogen oxides
In nitrogen monoxide, the mass ratio of O:N is r₁ = 1.142/1
In dinitrogen monoxide, the mass ratio of O:N is r₂ = 0.571/1
The ratio of the ratios is:
Ammonium is NH₄⁺ and Carbonate is CO₃⁻² => Ammonium Carbonate is (NH₄)₂CO₃
Answer:
15 protons
Explanation:
The atomic number always equals the number of protons inside the nucleus, so if the atomic number is 15, that means 15 protons are present.
Answer:
A Horizon - The layer called topsoil; it is found below the O horizon and above the E horizon. Seeds germinate and plant roots grow in this dark-colored layer. It is made up of humus (decomposed organic matter) mixed with mineral particles.
