Answer:
I,II, III
Explanation:
Firstly, the magnitude of nuclear charge affects the first ionization energy of an element. Hence,as effective nuclear charge increases, the attraction between the nucleus and the outermost electron increases and ionization energy consequently increases. Thus Mg has a higher first ionization energy than Be.
Secondly, oxygen has an electron configuration of 1s2 2s2 2p4 while nitrogen has an electron configuration of 1s2 2s2 2p3. Now, recall that extra energy is often associated with half filled orbitals hence nitrogen has a higher first ionization energy than oxygen. Furthermore, the addition of electron to an already half filled 2p orbital in oxygen (pairing) leads to inter electronic repulsion and drastic fall in first ionization energy. Therefore, as we move from nitrogen to oxygen in the periodic table, greater inter-electron repulsion between two electrons in the same p-orbital counter balances the increase in effective nuclear charge hence nitrogen has a greater first ionization energy than oxygen.
Lastly, the 3p orbital is far away from the nucleus hence we expect it to feel less of nuclear attraction than a 2p orbital. Hence the first ionization energy of Ar is less than that of Ne.
The answer is C. Glue gun melts a glue stick.
The kinetic energy theory of matter states that all particles of matter are in constant motion.
Kinetics has to do with some kind of movement, which is why this answer is the only plausible one.
Answer:
All of these three are polar molecules or ions
Explanation:
1) CO3 ^2-
It is a polar ion because it consists of one Oxygen atom and three carbon atoms so there is a substantial electroegativity difference between carbon and Oxygen due to which shared electrons are attracted more towards Oxygen creating partial negative charge on it and less towards carbon creating a partial positive charge on it, which makes the overall ion polar.
2) HCN
HCN is a polar molecule because there is substantial electronegativity difference between Carbon and Hydrogen as well as between Carbon and Nitrogen. Due to this negative charge is induced over Nitrogen because electronegativity of Nitrogen is 3.0 and positive charge on Carbon because its electronegativity is 2.5. The overall molecule is polar.
3) NO3^-1
Nitrate ion is also a polar molecule because there are three atoms of Oxygen and one atom of Nitrogen. There is substantial electronegativity difference between oxygen (3.44) and nitrogen (3.0) due to which partial positive charge is created on Nitrogen and partial negative charge created over three Oxygen atoms. The overall molecule is polar.
Hope it helps!
