Families of the Periodic Table. Remember that Mendeleev arranged the periodic table so that elements with the most similar properties were placed in the same group. A group is a vertical column of the periodic table.

The Periodic Table

The horizontal rows are called periods and the vertical columns are called groups. Elements in the same group have similar chemical properties. This is because they have the same number of outer electrons and the same valency.

Beside above, which three elements have the most similar chemical properties? Magnesium, strontium, and barium belong to group 2A of the periodic table. These have two valence electrons in their outermost shell. So these three elements have similar chemical properties.

Answer:The elements in the first column of the Periodic Table (other than hydrogen) are known as Group 1A metals, or alkali metals. When you compare the chemical properties of these elements (lithium, sodium, potassium, rubidium, cesium, and francium), what you’ll notice is that they are all remarkably similar.

As pictured below, notice how the elements lithium (Li), sodium (Na), and potassium (K) all look alike. They are all soft, silver metals. Since Li, Na, and K are all Group 1A metals, they all share similar chemical properties.

If two elements have the same arrangement of valence electrons, the world sees them similarly, and thus they have similar properties.

Metal

The number of valence electrons

Noble Gases

For groups 1-2 and 13-18, the valency is directly related to group number. So, elements in group one, the alkali metals, have one valence electron, those in group two have two valence, those in group thirteen have three electrons, and so on.

ALKALINE EARTH METALS

The elements in this family are fluorine, chlorine, bromine, iodine, and astatine. Halogens have 7 valence electrons, which explains why they are the most active non-metals. They are never found free in nature.

Boron

3

arsenic

Valency of First 30 Elements

The elements of group 15. The elements of the group 15 (column) VA of the periodic table all have electron configurations of s2p3, giving them five valence electrons. These elements include Nitrogen (N), Phosphorus (P), Arsenic (As), Antimony (Sb), and Bismuth (Bi).

Across each row, or period, of the periodic table, the number of valence electrons in groups 1–2 and 13–18 increases by one from one element to the next. Within each column, or group, of the table, all the elements have the same number of valence electrons.

Elements with the most valence electrons are in group 18.

The octet rule refers to the tendency of atoms to prefer to have eight electrons in the valence shell. When atoms have fewer than eight electrons, they tend to react and form more stable compounds.

Law of octaves, in chemistry, the generalization made by the English chemist J.A.R. Newlands in 1865 that, if the chemical elements are arranged according to increasing atomic weight, those with similar physical and chemical properties occur after each interval of seven elements.

six valence electrons

six Valence electrons