<span>1. Blocks Ultra violet rays that can be harmful.
2. Provides Oxygen, so we can live.
3. It blocks meteors from hitting Earth's surface.
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Answer : 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.
Solution : Given,
Mass of Cu = 300 g
Molar mass of Cu = 63.546 g/mole
Molar mass of
= 183.511 g/mole
- First we have to calculate the moles of Cu.

The moles of Cu = 4.7209 moles
From the given chemical formula,
we conclude that the each mole of compound contain one mole of Cu.
So, The moles of Cu = Moles of
= 4.4209 moles
- Now we have to calculate the mass of
.
Mass of
= Moles of
× Molar mass of
= 4.4209 moles × 183.511 g/mole = 866.337 g
Mass of
= 866.337 g = 0.8663 Kg (1 Kg = 1000 g)
Therefore, 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.
<span>Each atom in an ionic compound tends either to empty or complete the shell to 8 electrons. So when the number of electrons on the external shell is near 8 , the atom tends to attract electrons to complete the shell giving a positive ion called anion
Conversely when the number of electrons is small the atom gives these electrons to form a positive ion called a cation</span>
The energy generated by the movement of electrons is used to pump electrons across the inner mitochondrial membrane to an area of higher concentration. 17. Where do these protons (H+) come from? The originally came from a glucose molecule and were carried to the electron transport chain by NADH and FADH2.
The answer would be glucose molecule.
Answer:
Electrolytes are defined as those compounds which dissolve in a solvent such as water to produce a solution which conducts electric current easily.
Explanation:
Electrolytes are chemical compounds that dissolve in a solvent such as water and dissociate into ions (cations and anions) which helps to conduct electric current. They can be solids, liquids, or solutions and examples include all ionic compounds such as sodium chloride, calcium chloride, etc.
When electrodes are placed in a solution containing an electrolyte, the ions produced in the solution move from one electrode to the other. The negatively charged ions called anions are attracted to the positive electrode and the positively charged ions called cations are attracted to the negative electrode. This movement of ions generates an electric current. Electrolytes are also needed for the various electrochemical processes in living things and the main ions in these electrolytes are sodium (Na+), calcium (Ca2+), potassium (K+), magnesium (Mg2+), chloride (Cl-), etc.