<span>The chemical formula of Helium is He.
Question 1 :
Given n = 1.11 x 10^-6
To get no. of the particle,
No of particle = no. of mole x Avogadro Constant
p = n x NA
1 mol of Helium = 6.02 x 10^23
No of atoms = (6.02 x 10^23) x (1.11 x 10^-6)
= 6.66 x 10^17
................................
Question 2 :
Given p = 4.29x10^21
p = n x NA
4.29 x 10^21 = n x (6.02 x 10^23)
(4.29 x 10^21) / (6.02 x 10^23) = n
n = Approximately 7.126 x 10^-3
Hope the answer is right :)</span>
Answer:
Group 8 elements are inert and possess :
1. Low Boiling Points
2. High ionization energies
3. Electronegativities is very low
4. No color, odor
Explanation:
Group 8 elements are also called as Noble Gases. They are unreactive.
They have low boiling points means they remains monoatomic at room temperature. Having high ionization energy means that it is very difficult to remove an electron from its valence shell.
Answer:
a) 300K
b) 373K
c) 273K
Explanation:
to go from °C to K all you have to do is add 273.
Sound waves need to travel through a medium such as a solid, liquid, or gas. The sound waves move through each of these mediums by vibrating the molecules in the matter. The molecules in solids are packed very tightly. Liquids are not packed as tightly as solids. And gases are very loosely packed. The spacing of the molecules enables sound to travel much faster through a solid than a gas. Sound travels about four times faster and farther in water than it does in air. This is why whales can communicate over huge distances in the oceans. Sound waves travel about thirteen times faster in wood than air. They also travel faster on hotter days as the molecules bump into each other more often than when it is cold.
23.0 + 60.0 = 83.0° C heat energy is required to raise
