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In a row in the periodic table, as the atomic number increases, the atomic radius...

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jjzzzz | Student, College Freshman | (Level 1) Honors

Posted December 7, 2011 at 5:44 AM via web

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In a row in the periodic table, as the atomic number increases, the atomic radius generally does what. (increase, decrease, stays the same)

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ndnordic | High School Teacher | (Level 2) Associate Educator

Posted December 7, 2011 at 6:03 AM (Answer #1)

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In general, as you go across a row on the periodic table the atomic radius gets smaller. The reason for this is that the nucleus is getting larger and the densely packed, postively charged nucleus attracts the electrons toward itself more and more strongly.

The exception to this is the noble gases in group 18. They are always much larger than the corresponding element in group 17.

Note also, that the transition metals generally have about the same size atomic radius.

Sources:

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senioreeto | Student, Undergraduate | (Level 1) Valedictorian

Posted December 10, 2011 at 3:31 PM (Answer #2)

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in a row,the atomic radius does not increase as the atomic number increases becoz as we move from left to right in row,the electrons get added in the same valence shell and no new valence shell is formed.along with this,same number of protons also get added inside the nucleus.so the overall attraction of the nucleus for the valence shell remains the same as before,thats why the atomic radius remains uneffected.
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atyourservice | Student, Grade 10 | (Level 3) Valedictorian

Posted June 23, 2014 at 5:36 PM (Answer #3)

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In a row in the periodic table, as the atomic number increases, the atomic radius generally Decreases . 

This is because as the amount of electrons increase so does the force of the nucleus.

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