Explanation:
Thunderstorms, warm ocean water and light wind are needed for a hurricane to form (A). Once formed, a hurricane consists of huge rotating rain bands with a center of clear skies called the eye which is surrounded by the fast winds of the eyewall (B).
Answer:
There are 1.505×1023 molecules in 0.25 moles of oxygen.
answer : the correct option is, (B) 2, 3 and 6.
Answer: There are 3 unpaired electrons on aluminium in aluminium oxide.
Explanation:
Chemical formula of aluminium oxide is 
.
The atomic number of aluminium is 13 and its electronic configuration is 
. In order to complete its octet, aluminium will lose or donate 3 electrons to the oxygen atom as it has 3 electrons in excess.
Thus, there are three unpaired electrons on one aluminium atom.
Since, there are two aluminium atoms in , so, there will be in total 6 unpaired electrons on two aluminium atoms. Whereas each oxygen atom has deficiency of 2 electrons so, each aluminium atom will donate its excess of electrons to each oxygen atom.
Using the Equation: PV=nRT
Where P is the pressure 60 cmHg or 600 mmHg or 600/760= 0.789 atm
V is the volume 125 ml or 0.125 L, n is the number of moles, R is a constant 0.082057, and T is temperature 25 °C or 298 K;
Therefore:
0.789 × 0.125 = n × 0.082057 × 298
n = 0.0987/24.45
= 0.004036 mol
0.004036 mole has a mass of 0.286 g
Hence; 1 mole has a mass of 0.286/0.004036
= 70.8 g /mol
Therefore the molar mass of the gas is 71 g/mol (2 sfg)
