Hey there!:
The 1s, 2s and 2p subshells are completely filled (a maximum of two electrons go into the 1s subshell and a maximum of two electrons go into the 2s subshell. The 2p subshell includes 3 orbitals, with 2 electrons maximum per orbital). The 3s subshell has only one of a maximum of two electrons.
Hope that helps!
Atomic Number. It represents the number of protons in an atom of a particular element, which is what identifies that particular element. If the number of protons is different, the element is different.
The cations has positive charges that are metals while the anions have negative charges that are non-metals. Upon reaction, there is an exchange in charges that are reflected in the subscripts of the atoms. In this case, compound AX2 must have a cation, A belonging to group 2 A with +2 charge and anion, X belonging to Group 7A with -1 charge. Answer is D.
Velocity is defined as displacement over time. Could you have possible meant viscosity? If so, viscosity is defined as the state of being thick, sticky, and semifluid in consistency, due to internal friction. And example of a substance with a high viscosity would be honey.
