It increases because the outermost electrons are attracted more strongly by protons. It decreases because the effective nuclear charge decreases while moving left to right. In an atom In an atom: The nucleus is made of electrons and protons.

Moving down the group the number of shells increases. Therefore, the number of core electrons increases which results in shielding the valence or bond pair electrons. Hence, electrons will be less attracted by the nucleus.

Electronegativity increases across a period and decreases down a group. Down a group, the number of energy levels (n) increases, and so does the distance between the nucleus and the outermost orbital.

On the periodic table, electronegativity generally increases as you move from left to right across a period and decreases as you move down a group. As a result, the most electronegative elements are found on the top right of the periodic table, while the least electronegative elements are found on the bottom left.

Both sodium and chlorine have their bonding electrons in the 3-level. It is no wonder the electron pair gets dragged so far towards the chlorine that ions are formed. Electronegativity increases across a period because the number of charges on the nucleus increases.

Why does electronegativity increase across a period? Consider sodium at the beginning of period 3 and chlorine at the end (ignoring the noble gas, argon). Electronegativity increases across a period because the number of charges on the nucleus increases. That attracts the bonding pair of electrons more strongly.

Well the electronegativity increases across the period because the electrons are being added onto the same energy level,this increases the number of electrons of an atom,the increase of electrons of an atom also leads to increase in clear charge,in fact the nuclear charge increases more,this leads to attraction of …

The electronegativity also increases up a group (column) of the periodic table. Lithium 1.0 and Francium 0.7 in Group I. Therefore Francium (Fr) in the lower left Group I Period 7 has the lowest electronegativity value at 0.7 and Fluorine (F) upper right Group 17 Period 2 has the highest electronegativity value at 4.0.

Description of trend The graph shows how atomic radius varies across period 3: as the atomic number increases, the atomic radius decreases.

Phosphorus, sulfur, chlorine and argon There are are van der Waals’ forces between its atoms. The melting and boiling points of these elements are very low because: van der Waals’ forces are very weak forces of attraction … little energy is needed to overcome them.

Melting and boiling points increase across the three metals because of the increasing strength of their metallic bonds. The number of electrons which each atom can contribute to the delocalized “sea of electrons” increases. The atoms also get smaller and have more protons as you go from sodium to magnesium to aluminum.

32 elements

The period 6 transition metals are lanthanum (La), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), and mercury (Hg).

In the sixth period (n = 6) of the periodic table, 6s, 4f, 5d and 6p orbitals are filled in the increasing order of the energy. Total 16 orbitals are available each of which contains a maximum 2 electrons. Thus, the sixth period can accommodate maximum 32 elements.

SALIENT FEATURES OF GROUP 14 (CARBON FAMILY) ELEMENTS

tin

Group 14 is the carbon family. The five members are carbon, silicon, germanium, tin, and lead. All of these elements have four electrons in their outermost energy level. Of the Group 14 elements, only carbon and silicon form bonds as nonmetals (sharing electrons covalently).

Carbon group element, any of the six chemical elements that make up Group 14 (IVa) of the periodic table—namely, carbon (C), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), and flerovium (Fl).

Sn

The group 14 is also called the carbon family of the carbon group. Sometimes it is also called crystallogens. The first element in this group is carbon, and hence, this is called a carbon group.

Group 14 has 4 electrons in its outermost shell. So, it can either gain or loose for electrons to complete its octet. So, they do not form ionic bond usually. …

Since calcium lost two electrons, it has 20 protons, but only 18 electrons. This makes calcium a positive ion with a charge of 2+. Since each chlorine atom gained an electron, they each have 17 protons and 18 electrons.

What is an anion? An anion has more electrons than protons, consequently giving it a net negative charge. For an anion to form, one or more electrons must be gained, typically pulled away from other atoms with a weaker affinity for them.

Anions are negatively charged ions. They are formed when non-metal gains the electrons. Therefore, they possess a net negative charge. Some examples of anions are Iodide (I–), chlorine (Cl–), hydroxide (OH–).

Here are several examples of anions:

• Bromide – Br. –
• Chloride – Cl. –
• Fluoride – F. –
• Iodide – I. –
• Nitride – N. 3-
• Oxide – O. 2-
• Sulfide – S. 2-

Once they reach our bloodstream, negative ions are believed to produce biochemical reactions that increase levels of the mood chemical serotonin, helping to alleviate depression, relieve stress, and boost our daytime energy.