Answer:both
Explanation:
It depends on where your looking at it from
Types of Bonds can be predicted by calculating the
difference in electronegativity.
If, Electronegativity difference is,
Less
than 0.4 then it is Non Polar Covalent Bond
Between 0.4 and 1.7 then it is Polar Covalent Bond
Greater than 1.7 then it is Ionic
For N and Se,
E.N of Nitrogen = 3.04
E.N of Selenium = 2.55
________
E.N Difference
0.49 (Weakly Polar Covalent)
As you have not provided remaining pairs, so if you have any of them, follow the method as mentioned above.
Answer:
Helium is also the second simplest of the chemical elements. Its atoms consist of two protons, two neutrons, and two electrons. Only the hydrogen atom is simpler than a helium atom. The hydrogen atom has one proton, one electron, and no neutrons.
Explanation:
An element is a pure substance
Answer:
An increase in entropy
Explanation:
In ice, the molecules are very well ordered because of the H-bonds. As ice melts, the intermolecular forces are broken (requires energy), but the order is interrupted (so entropy increases). Water is more random than ice, so ice spontaneously melts at room temperature.
Just think about this rationally. Melting ice (or anything) will require heat put in (this is called the latent heat of fusion), so you automatically know that the change in enthalpy is going to be positive. In order to make the reaction spontaneous, delta G, the Gibbs free energy has to be negative. So now look at the formula Delta(G) = Delta(H) - T*Delta*(S). If you know that g is negative, and H is positive, then it is only possible if -T*Delta(S) is negative. If that is positive, then Delta(S) has to be positive. So theres your answer :). An increase in entropy
