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The alkali metals can be found on period one of the periodic table of elements. Following is a list of atomic radii for these elements.
Li - 145 pm
Na - 180 pm
K - 220 pm
Rb - 235 pm
Cs - 260 pm
Fr - unknown
Wiki User
∙ 12y ago
Wiki User
∙ 12y agoHonestly,
I don't know if this will help you but this is what I found on
http://en.wikipedia.org/wiki/Atomic_radius
"Atomic radii vary in a predictable and explicable manner across the Periodic Table. For instance, the radii generally decrease along each period (row) of the table, from the alkali metals to the noble gases; and increase down each group (column). The radius increases sharply between the noble gas at the end of each period and the alkali metal at the beginning of the next period. These trends of the atomic radii (and of various other chemical and physical properties of the elements) can be explained by the electron shell theory of the atom; they provided important evidence for the development and confirmation of quantum theory."
Wiki User
∙ 16y agoLithium = 3
Sodium = 11
Potassium = 19
Rubidium = 37
Cesium = 55
Francium = 73
Wiki User
∙ 8y agoIt is increasing down in the group. Li has the smallest.
Wiki User
∙ 8y agoLithium: 182 picometres,Sodium: 227 pm
Potassium: 275 pm
Rubidium: 303 pm
Caesium: 343 pm
Francium: 348 pm.
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Do the elements to the right of the periodic table have small or large radii?
Across a period the atomic size decreases. Hence elements in the right side of the periodic table have small size / radii.
Why melting point decrease down the group for Alkali metals but increase for Halogens?
Because the atomic radius increases down the group 1 and decreases down the group of halogen
What trend can be observed among the atomic radii of main-group elements down a group?
Within a group, the number of shells (or energy level) increases (as we go from top to bottom of a group) and hence the size of the atom or the atomic radii increases.
Why frankel defect is not seen in alkali metals?
because of large difference in size
What is the general configuration of s-block elements?
The s-block elements consist of the alkali metals and alkaline earth metals, including hydrogen and helium. Most reactions of s-block elements involve the loss of an electron to form a singly positively charged ion.
What are the two variables that affect atomic size?
Alkali metals and noble gases
Define atomic radii?
The atomic radii is the measure of the size of the atoms in a chemical element. This is the distance from the nucleus to the boundary of the electrons' cloud.
What trend do you note for the atomic radii of period 3?
The size of atom decreasing.
Why are alkaline earth metals harder than alkali metals?
i thought increase in size.
Do the elements to the right of the periodic table have small or large radii?
Across a period the atomic size decreases. Hence elements in the right side of the periodic table have small size / radii.
Why do halogens have the smallest atomic radii in their respective periods?
Halogens have maximum effective nuclear charge. So the high number of protons in the nucleus attract electrons and thus the size of the atomic radii is the smallest.
What elements has the smallest atomic size K Ca Na Ar or Kr?
Ar, using the table of atomic radii in wikipedia.
What trend can be observed among the atomic radii of main-group elements down a group?
Within a group, the number of shells (or energy level) increases (as we go from top to bottom of a group) and hence the size of the atom or the atomic radii increases.
Why frankel defect is not seen in alkali metals?
because of large difference in size
Why melting point decrease down the group for Alkali metals but increase for Halogens?
Because the atomic radius increases down the group 1 and decreases down the group of halogen
The range in size of most atomic radii is approximately?
The Smaller Atoms [H to Ca] are in the [single] Angstrom range.
The alkaline earth element having the largest atomic radius is found in period?
7th period because atomic size down the group increases. And Alkali Earth metals are found only in Group 1. The element is in Group 1 and period 7
