Answer:
a) False
b) False
c) True
Explanation:
a) Most sulfur oxides formed during combustion come from sulfur in the air: The sulfur burns in presence of oxygen to produce sulfur oxides, the source of sulfur is anthropogenic activities (Human activities).
So the given statement is false.
b) A flue gas scrubber removes SO2 pollution in a coal-fired power plant by using lime to convert the SO2 into alcohols:
False
The lime reacts with sulfur dioxide to give carbon dioxide and calcium sulfite.
c) True
c)
Answer:
Yes. The two elements can combine to form different compounds.
Explanation:
Two elements can combine at different ratios.
Consider CO and CO₂. Both are made from carbon and oxygen. However, C and O combine at a 1:1 ratio in CO but at a 1:2 ratio in CO₂. CO is a fuel; it burns in the air. CO₂ does not burn in the air; it is used to put out fires and is found in extinguishers. CO and CO₂ are two distinct compounds.
There are many ways for the elements to combine with each other. As a result, the first twenty elements on the periodic table alone can produce a large number of compounds.
Answer: Option (4) is the correct answer.
Explanation:
It is known that density is mass divided by volume.
Mathematically, Density = 
Since, density is directly proportional to mass. So, more is the mass of an element more will be its density.
Mass of magnesium is 24.305 g/mol.
Mass of barium is 137.327 g/mol.
Mass of beryllium is 9.012 g/mol
Mass of radium is 226 g/mol.
Hence, radium has more mass therefore it will have the greatest density at STP.
The correct option is SILT.
Terminal velocity refers to the constant speed with which an object fall under the force of gravity. The smaller the weight of the object, the faster will be the rate of falling of the objects. From the options given above, it is silt that has the smallest particle size and the right texture to achieve the highest terminal velocity.<span />
Start by converting mg to g. There is .001g in every miligram, so there is 0.4g in this sample.
Then find the molar mass of ibuprofen (C13H18O2) which is 206.3g/mol
Then divide grams by the molar mass to get moles of C13H18O2: (0.4g)/(206.3g/mol) = 1.94x10^-3mol C13H18O2
Then multiply moles by Avogadro's number to get molecules: (1.94x10^-3mol)/(6.02x10^23) = 1.17x10^21 molecules of ibuprofen (C13H18O2)
