Answer:
The ancient Greeks believed in the four elements of air, earth, fire, and water. The Greek philosopher Empedocles is known for originating the theory of these classic four elements being the basis of all things.
Answer:
Unidentified flying object or fly saucer.
Explanation:
Answer: (3) The difference in electronegativity between carbon and oxygen is greater than that between fluorine and oxygen.
Explanation: Polarity of a molecule is due to the difference in electronegativity of the atoms. More is the electronegativity difference, more is the polarity.
Electronegativity of carbon = 2.5
Electronegativity of oxygen = 3.5
Electronegativity of fluorine = 4.0
Thus the difference in electronegativity of carbon and oxygen is=(3.5-2.5)= 1.0
Thus the difference in electronegativity of fluorine and oxygen is=(4.0-3.5)= 0.5.
Thus C-O bond is more polar than F-O bond.
Explanation:
Acceleration (a) = 600 m/s²
Mass (m) = 300 kg
Force (F) = ?
We know
F = m * a
= 300 * 600
=180000 Newton
The force acting on the object is 18000 Newton.
It has to be understood that 2 moles of oxygen are there in each mole of PbO2. Then it has to be calculated for 2 moles of oxygen.
Amount of oxygen = 2 * 5.43 moles
= 10.86 moles
Now it is also a fact that each mole of H2O contains 1 mole of oxygen. Then it can be easily concluded that 10.86 moles of water will be produced. I hope the procedure is clear enough for you to understand.