2007-01-18 17:24:55 · 4 answers · asked by Onions 2 in Science & Mathematics ➔ Chemistry
very simple!!
the main criteria for any element to be in a group is the valence shell(i.e s,p,d,f) where its valence electron is situated.
like Sodium, potassium, lithium, magnesium, calcium etc fall in s-group.
you can try it out yourself.
have fun!!!
2007-01-18 17:47:22 · answer #1 · answered by Arjun V 2 · 0⤊ 0⤋
Elements in the same group have similar or same reactivities to other elements. That means the compounds formed are usually similar in proportion. For example, Na reacts with Chlorine to form a compound NaCl with one Na and one Chlorine, not two or three.Lithium in the same group as Na also reacts with Chlorine also to form a compound with one Chlorine in LiCl.
This is because the elements in the same group have the same valence shell electronic configuration- the basis of all chemical properties.
Consider the Carbon group - this group is able to bond with 4 other elements. So does Silicon under it. Lead at the bottom similarly can form 4 bonds. However, it can also form just 2. Nonetheless, the number of bonds is even number. So, within a group there are common trends. Also, the noble or inert gases as a group are usually monatomic and will not combine or react with other elements. There are exceptions, though but the trend is there. In chemistry, it is the trend that is important. It is not "HARD AND FAST" rule.
2007-01-19 02:03:32 · answer #2 · answered by Aldo 5 · 0⤊ 0⤋
The number of electrons in their outer electron shells.
2007-01-19 02:28:10 · answer #3 · answered by Anonymous · 0⤊ 0⤋
The same consistancy. Metals are metallic, Gasses are gas... etc. However their are exceptions such as mercury.
2007-01-19 01:36:54 · answer #4 · answered by sar11572 2 · 0⤊ 0⤋