Final answer:
Elements on the periodic table are grouped based on similar chemical properties, with Na and K in the alkali metals; Ca and Mg in alkaline earth metals; Zn as a transition metal; Si as a metalloid; N and O as nonmetals; F and Br as halogens; Ne as a noble gas; and U in the actinides. The order of increasing atomic radius among Si, Cl, Ca, and Sr is based on their periodic table positions.
Step-by-step explanation:
The elements given can be classified into groups based upon their similar chemical properties and their position on the periodic table:
- Alkali Metals (Group 1): Na, K
- Alkaline Earth Metals (Group 2): Ca, Mg
- Transition Metals (Groups 3-12): Zn (group 12)
- Metalloids (Stair-stepped line): Si
- Nonmetals (Groups 14-16): N, O (Group 16)
- Halogens (Group 17): F, Br
- Noble Gases (Group 18): Ne
- Actinides (Period 7): U
As elements in the same group exhibit similar chemical characteristics due to having the same number of valence electrons.
Based on their positions in the periodic table, the following atoms in order of increasing radius would be: Si, Cl, Ca, Sr. Generally, atomic radius decreases across a period from left to right and increases down a group. Silicon (Si) being in Group 14 has a smaller atomic radius than calcium (Ca) in Group 2 because Si is to the right of Ca in the same period. Chlorine (Cl) being in the same period as silicon but to its right has a smaller atomic radius. Strontium (Sr) is below calcium (Ca) in Group 2, therefore, it has a larger atomic radius.