Answer:
Let x moles of silicon contains 2.8x10^24 atoms. 6.02x10^23 atoms are present in 1 mole of Si. Therefore 2.80x10^24 atoms are present in = 2.8x10^24/6.02x10^23 = 4.65 moles of Si.
Explanation:
Answer : The density of the block is estimated to be, 
.
Explanation :
Density of the water, 
As we know that,
Buoyant force = 
where,
g = gravitational acceleration
volume of the block = v
density of the block = 
Weight of the Block = Buoyant force exerted by water
Thus, the density of the block is estimated to be, .
Answer:
(b) BeF2 > OF2 > CH3OH
Explanation:
The degree and type of intermolecular forces present in a substance influences its vapour pressure considerably. The greater the magnitude and strength of intermolecular forces in the substance, the lower the vapour pressure of the substance.
BeF2 molecules are held together by weak vanderwaals forces hence BeF2 will exhibit the least degree of intermolecular interaction and have the highest vapour pressure. OF2 molecules are bound together by dipole interactions hence it will exhibit a lower vapour pressure compared to BeF2. CH3OH molecules form hydrogen bonds with water molecules hence it will exhibit the least vapour pressure among the trio.
Answer:
Measurements are so often taken for granted we sometimes do not appreciate the grand importance measurements play in our lives. On a baseline level, measurements fall into the categories of weight, area, volume, length and even temperature. While we look at these various categories as stoic forms of mathematical measurements a closer examination of things we do in everyday life reveals their clear importance.
Explanation:
Measurements provide structure and remove the chaos that would result without any congruent method of understanding weight, mass, temperature, etc.
