Explanation:
As you move across the periodic table, the number of protons and neutrons increases but the number of orbital levels of the period remains the same. The atomic radii therefore decrease, across the period, because the increase in proton number causes an increased pull of the orbital electrons bringing them closer to the nucleus.
As you move down a group in a periodic table, the number of orbital levels increase. The effective nuclear charge of the nucleus of the atoms decreases due to the increased number of orbital levels that shield the valence electrons from the attractive force nucleus.
Answer:
Option B, HCO3 1-
Explanation:
The valence of Sodium ion is +1 and the valence of HCO3 is -1. Thus, sodium ion has an extra electron to be donated to complete its outer shell while HCO3 needs an electron to complete its outer shell
Hence Na will combine with HCO3 to form NaHCO3
Option B is correct
I always thought it was a mixture but can also be a compound
Answer:
See explanation
Explanation:
Electron affinity is the energy released when an extra electron is added to a neutral gaseous atom. A negative value of electron affinity indicates that energy is given out and vice versa.
Metals have positive electron affinity since electrons rarely accept electrons, so;
Na(g)+ 1e^- → Na^-(g) positive
Mg(g)+1e^- → Mg^-(g) positive
For the last case; Br(g)+ 1e^- → Br^-(g), the electron affinity for the non-metals is negative. hence the answer
