atoms tend to gain,lose,and share valence electrons until each atom had the same number of valence electrons as the

most stable noble gas. This is known as the octet rule, which states that atoms tend to gain, lose, or share electrons in order to attain a stable electron configuration similar to the noble gases.

To understand how atoms achieve stable electron configurations, it helps to know the valence electrons. Valence electrons are the outermost electrons in an atom's electron cloud and are responsible for the chemical behavior of an element. The number of valence electrons determines the element's placement in the periodic table and its propensity to form chemical bonds.

To find the number of valence electrons for an atom, you can refer to the periodic table. For elements in groups 1-2, the number of valence electrons corresponds to the group number. For example, elements in group 1 (such as hydrogen and sodium) have 1 valence electron, and elements in group 2 (such as beryllium and magnesium) have 2 valence electrons.

For elements in groups 13-18, the number of valence electrons can be determined by subtracting the group number from 10. For example, elements in group 13 (such as boron) have 3 valence electrons (10 - 13 = 3), and elements in group 16 (such as oxygen) have 6 valence electrons (10 - 16 = 6).

Once you know the number of valence electrons for an atom, you can determine how it will interact with other elements to achieve a stable electron configuration.

Atoms tend to gain or lose electrons to achieve a full outer shell (usually 8 electrons, with the exception of hydrogen and helium) and attain the electron configuration of the nearest noble gas. For example, sodium (Na) in group 1 has 1 valence electron. To achieve the electron configuration of the noble gas neon (Ne), which has a full outer shell, sodium will tend to lose this 1 valence electron and become positively charged (Na+).

On the other hand, elements like chlorine (Cl) in group 17 have 7 valence electrons. To achieve the electron configuration of the noble gas argon (Ar), which has a full outer shell, chlorine will tend to gain 1 electron and become negatively charged (Cl-).

Lastly, some atoms will share valence electrons through covalent bonds to achieve a stable outer shell. This occurs between nonmetal atoms that do not have the capability to easily lose or gain electrons, such as carbon (C) or oxygen (O). In a covalent bond, two atoms share one or more pairs of electrons, forming a molecule. Each atom contributes some of its own valence electrons to the shared pool to achieve a full outer shell.

In summary, atoms tend to gain, lose, or share valence electrons to achieve a stable electron configuration similar to the nearest noble gas. This behavior is governed by the octet rule and determines the chemical properties and reactivity of elements. The number of valence electrons for an atom can be determined by its position on the periodic table.

That's a wide open question. What choices do you have?

outermost shell holds maybe ?

like maybe
If the outer shell holds 8, like Li to Ne, the second row in the periodic table
Li can lose one (Li+) to leave none in shell 2 and leave the inner shell which holds 2 when full
F has 7 but the outer shell holds 8 so it wants to grab one and become F-
Ne gas is noble and has exactly 8 in that outer shell so is happy and does not want to grab or lose any.