They increase from left to right.
As you move from left to right across the periodic table, the number of valence electrons increases by one at a time. This increase results in a higher effective nuclear charge, which leads to increased attraction between the nucleus and the electrons. This can affect the reactivity and chemical properties of the elements in that period.
The number of valence electrons increases from left to right across a period.
Atomic size increases from top to bottom in a group due to increase in theshieldingeffect.As you go down the group shielding from core electrons increases (as more core electrons are added), therefore valence electrons experience weaker attraction forces from the nucleus and are located further away from it, resulting in an increase in size.If you move across a period the attraction between the nucleus and valence electrons increases because the number of protons and the number of valence electrons both go up whereas the number of core electrons stays the same (shielding decreases). In this case the size decreases.
stays the same Well... that's not really true... the number of them stays the same, but several things happen to them. First off they are further from the nucleus. And they are further shielded by additional electrons between the valence and nucleus. This causes a looser association and tends to make the atom more volatile.
The number of valence electrons for the elements increases across a period, from 1 (group 1) to 8 (group 18).
Electronegativity is affected by: atomic number of the element, distance between the nucleus of an atom and the valence electrons or sometimes by the so-called "d-block contraction".
The number of valence electrons increases as you go across a period. For example in period 2 the number of valence electrons rises from 1 in Li up to 8 in neon.
As you move from left to right across the periodic table, the number of valence electrons increases by one at a time. This increase results in a higher effective nuclear charge, which leads to increased attraction between the nucleus and the electrons. This can affect the reactivity and chemical properties of the elements in that period.
The number of valence electrons increases from left to right across a period.
Atomic size increases from top to bottom in a group due to increase in theshieldingeffect.As you go down the group shielding from core electrons increases (as more core electrons are added), therefore valence electrons experience weaker attraction forces from the nucleus and are located further away from it, resulting in an increase in size.If you move across a period the attraction between the nucleus and valence electrons increases because the number of protons and the number of valence electrons both go up whereas the number of core electrons stays the same (shielding decreases). In this case the size decreases.
The number of valence electrons remains the same as you move across a row on the periodic table. For example, in row 2 (elements from Li to Ne), all elements have 2 valence electrons. However, the chemical reactivity of these valence electrons can change as you move across the row due to the increasing nuclear charge affecting their interactions with other atoms.
The number of valence electrons for the elements increases across a period, from 1 (group 1) to 8 (group 18).
stays the same Well... that's not really true... the number of them stays the same, but several things happen to them. First off they are further from the nucleus. And they are further shielded by additional electrons between the valence and nucleus. This causes a looser association and tends to make the atom more volatile.
The number of valence electrons increases by one as you move from left to right across a period in the periodic table. Sodium (Na) has 1 valence electron, magnesium (Mg) has 2 valence electrons, aluminum (Al) has 3 valence electrons, silicon (Si) has 4 valence electrons, phosphorus (P) has 5 valence electrons, sulfur (S) has 6 valence electrons, chlorine (Cl) has 7 valence electrons, and argon (Ar) has 8 valence electrons.
The number of valence electrons for the elements increases across a period, from 1 (group 1) to 8 (group 18).
Electronegativity generally increases across a period from left to right due to an increase in effective nuclear charge, making it harder for atoms to release electrons. It tends to decrease down a group as the atomic size increases, leading to weaker attraction for valence electrons.
The atomic radii decrease from sodium to chlorine due to the increase in effective nuclear charge as you move across the period. This results in a stronger pull on the valence electrons, causing the atomic size to decrease. Additionally, the increased number of protons in the nucleus as you move from sodium to chlorine also contributes to this decrease in atomic size.