Question

The number of valence electrons across a period and down the group.
A.Increases, same
B.Decreases, same
C.Same, increases
D.Increases, decreases

Answer 1

In the periodic table when we move left to right, each new electron is added in an adjacent atom. As we move down the groups, the groups have a property of maintaining the number of electrons in the outermost shell.

Complete step by step answer:
Periodic table is the arrangement of elements that had known to exist in increasing sequence, from left to right, of their atomic number.
Elements are arranged in table format in which the properties of the elements repeat themselves after a certain interval. Elements are arranged in rows and columns. Rows are the horizontal lines in which elements are arranged from left to right in increasing order and columns are the vertical lines from top to bottom.
Elements in the same group follow almost similar properties. They have the same number of electrons. For example the elements of group number 1 are Lithium, Sodium, Potassium, Rubidium and Cesium all have one electron in their valence shell, our outermost shell.
While talking about period, in a period since atomic number increases by one hence 1 new electron adds up at subsequent steps. That is why the number of electrons increases as we move along the period.

Hence, the correct option is option A.

Note:
They are certain elements that show anomalous behavior. These are generally the first element of each group. Due to their small size, high ionization energy and high electronegativity they show anomalous behavior or different behavior from the rest of the elements of their group.