There are more than two such atoms.
Perhaps there was a list of atoms you had to chose from.
Anyway, two such atoms are beryllium and magnesium.
Helium and neon will have their outer energy level filled with two electrons. Helium has 2 electrons in its only energy level, while neon has 8 electrons in its second energy level.
Carbon has four electrons in the outermost energy level, which is energy level two. It needs eight electrons to have this energy level filled.
undiscovered...yet, but there are a few...go forward 50 years and see
An atom with an incompletely filled outermost energy level is likely to be reactive. This is because atoms tend to gain, lose, or share electrons to achieve a stable outer electron configuration. Atoms with incomplete outermost energy levels are looking to fill or empty their outermost energy level to achieve stability.
Electrons in the outermost energy level (valence electrons) have the highest energy level. These electrons are involved in the atom's chemical reactions and bonding with other atoms.
Helium and neon will have their outer energy level filled with two electrons. Helium has 2 electrons in its only energy level, while neon has 8 electrons in its second energy level.
Carbon has four electrons in the outermost energy level, which is energy level two. It needs eight electrons to have this energy level filled.
undiscovered...yet, but there are a few...go forward 50 years and see
Helium atoms only need 2 valence electrons to have a filled outermost energy level because helium is in the first period of the periodic table and its outermost energy level can only hold a maximum of 2 electrons.
There are more than two such atoms. Perhaps there was a list of atoms you had to chose from. Anyway, two such atoms are beryllium and magnesium.
Helium only needs two electrons to have a filled outermost energy level.
An atom with an incompletely filled outermost energy level is likely to be reactive. This is because atoms tend to gain, lose, or share electrons to achieve a stable outer electron configuration. Atoms with incomplete outermost energy levels are looking to fill or empty their outermost energy level to achieve stability.
8 electrons
Carbon has four electrons in the outermost energy level, which is energy level two. It needs eight electrons to have this energy level filled.
Helium.
Electrons in the outermost energy level (valence electrons) have the highest energy level. These electrons are involved in the atom's chemical reactions and bonding with other atoms.
Maximum of 8 electrons in second energy level.