Answer:
Since in a chloride ion, we have an additional electron
you might think that it will affect the mass but the mass of an electron is almost negligible so we will ignore that
Amount of ions in 1 mol = 6.022 * 10^23
Amount of ions in 0.486 moles = 0.486 * (6.022*10^23)
Amunt of ions in 0.486 moles = 2.9 * 10^23 ions
Hence, option 1 is correct
Bonds of two atoms of equal electronegativity are nonpolar covalent bonds.
Your second sentence is identical to the first sentence; I'll bet the second sentence is "Bonds between two atoms that are unequally electronegative are polar covalent bonds."
Answer: Option (c) is the correct answer.
Explanation:
A chemical reaction is defined as the reaction where a chemical bond will break in order to form a new bond due to the formation of a new substance.
For example, 
Here, NaCl is the new substance that is formed. A chemical reaction will always bring change in chemical composition of a substance.
The production of hydrogen gas from water, the tarnishing of a copper penny, charging a cellular phone and burning a plastic water bottle are all chemical reactions.
Whereas a reaction where no change in chemical composition of a substance takes place is known as a physical reaction.
For example, chopping a log into sawdust will change the shape but it will not bring any change in chemical composition of the substance.
Thus, we can conclude that in the following list, only chopping a log into sawdust is not an example of a chemical reaction.
Answer:

Explanation:
The number of molecules of KCN can be found by using the formula
<h3>N = n × L</h3>
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
N = 0.00048 × 6.02 × 10²³
We have the final answer as

Hope this helps you
Hey there!
Molar mass N2 = 28.01 g/mol
Therefore:
28.01 g N2 -------------- 6.02*10²² molecules N2
( mass N2 ?? ) ----------- 25,000 molecules N2
mass N2 = ( 25,000 * 28.01 ) / ( 6.02*10²³ )
mass N2 = 700250 / 6.02*10²³
mass N2 = 1.163*10⁻¹⁸ g
Hope that helps!