In the ocean, light is used by phytoplankton in order to produce sugar. 10% of the energy from the sun is available to the zooplankton that eat the phytoplankton, the rest of the energy is lost as heat or through powering body building/functions/reproduction. Whatever eats the zooplankton receives 10% of that energy in order to grow
Answer:The world population increased from 1 billion in 1800 to 7.7 billion today. The world population growth rate declined from 2.2% per year 50 years ago to 1.05% per year. Other relevant research: World population growth – This article is focusing on the history of population growth up to the present.
Explanation:
Answer: 
.
Explanation:
If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
Mass of K = 49.4 g
Mass of S = 20.3 g
Mass of O = 30.3 g
Step 1 : convert given masses into moles.
Moles of K=
Moles of S= \frac{\text{ given mass of S}}{\text{ molar mass of S}}= \frac{20.3g}{32g/mole}=0.63moles[/tex]
Moles of O = \frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{30.3g}{16g/mole}=1.89moles[/tex]
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For K = 
For S =
For O =
The ratio of K: S:O = 2: 1: 3
Hence the empirical formula is .
Answer:
D. 0.543kg of copper metal is produced from 0.680kg of copper 1 sulphide.
Explanation:
First write the equation for the reaction:
Cu2S + O2 ------> 2Cu + SO2
Determine the mole ratio of the two substances:
I mole of Cu2O forms 2 moles of Copper metal
The number of moles of copper 1 sulphide used is;
n = mass of Cu2S / molar mass of Cu2S
Mass = 0.680kg = 680g
Molar mass = 159.16g/mol
n = 680g / 159.16g/mol
n = 4.272moles
Determine the number of mole of copper:
Number of moles of copper metal produced from 4.272moles of copper 1 sulphide is therefore:
n of copper = 2 * 4.272 Moles
n = 8.544moles.
Determine the mass copper:
The mass of copper metal produced is therefore = number of moles of copper * molar mass of copper
mass = 8.544 moles * 63.55g/mol
mass = 542.97grams
Mass = 0.543kg
