Classification of Matter A.1 Periodic Table Elements Classification (id: 23e2c21

本题目来源于试卷: Classification of Matter A.1 Periodic Table Elements Classification，类别为 IB化学

[单选题]
For elements in the same row X or couwt7-wd3 rewz43o vf,lumn Y of the per07b.mxgc u 7sriodic table, some features of the outer electron shell remain cogrbc x7 ms7.0unstant.

Which of the following is correct?

A. Name of X is Period ; Name of Y is Group ; Number of electron shells is Constant across X ; Number of outer shell electrons is Constant down Y
B. Name of X is Period ; Name of Y is Group ; Number of electron shells is Constant down Y ; Number of outer shell electrons is Constant across X
C. Name of X is Group ; Name of Y is Period ; Number of electron shells is Constant across X ; Number of outer shell electrons is Constant down Y
D. Name of X is Group ; Name of Y is Period ; Number of electron shells is Constant down Y ; Number of outer shell electrons is Constant across X


参考答案:  A


本题详细解析:
Explanation:

Elements in the same group (column) of the periodic table have the same number of outer shell (valence) electrons, represented by the group number; the number of electron shells increases down the group. Elements in the same row (period) have the same number of electron shells (or principal quantum number), equal to the period number; the number of valence electrons increases across the period. This question is moderately difficult as the student must recall multiple pieces of information and correctly interpret a schematic illustration of the periodic table.

微信扫一扫，分享更方便