Q. What is the outer shell of an atom?
Valence Electrons The valence shell is the outermost shell of an atom in its uncombined state, which contains the electrons most likely to account for the nature of any reactions involving the atom and of the bonding interactions it has with other atoms.
Q. What is the outside of an atom called?
The outermost regions of the atom are called electron shells and contain the electrons (negatively charged). Atoms are made up of protons and neutrons located within the nucleus, with electrons in orbitals surrounding the nucleus.
Q. Why outermost shell is called valence shell?
-The number of electrons to be filled in each shell depends on Aufbau’s principle and Hund’s rule. Valency tells us only the total number of electrons present in the outermost shell of the atom and so it is different from the atomic number. Therefore, the outermost shell of an atom is known as valence shell.
Q. What elements have 2 electrons in the outer shell?
Helium has 2 electrons — both in the first shell (so two valence electrons). Lithium has 3 electrons — 2 in the first shell, and 1 in the second shell (so one valence electron).
Q. Why are there 8 electrons in the outer shell?
In general, atoms are most stable, least reactive, when their outermost electron shell is full. Most of the elements important in biology need eight electrons in their outermost shell in order to be stable, and this rule of thumb is known as the octet rule.
Q. Why is Magic Number 8 valence electrons?
Because 8 electrons is enough to fill up the first two subshells. After that point any more electrons are going to be added to subshells that are higher energy meaning that they are not going to be as tightly bound (since that’s pretty much what higher energy means in this context).
Q. Why is it important to have 8 electrons?
The Significance of “8” in Chemistry The rule of 8 or the Octet rule is the tendency of atoms to have eight electrons in their valence shell. Eight electrons in this final shell allow atoms to be stable and non-reactive. Atoms tend to be reactive when their valence shell (or outermost shell) is incomplete.
Q. Why do atom need electrons?
They neutralise the charge of an atom, their negative charge balancing out the positively charged protons; that is why there’s always an equal number of electrons and protons in an atom. Electrons are also responsible for atom bonding.
