Question

Position in the periodic table.

1. What is the difference between a period and a group on the periodic table of elements?
2. How does the number of valence electrons in sodium (Na) compare to the number of
valence electrons in calcium (Ca)?
A. Na has one more valence electron than Ca.
B. Na and Ca have an equal number of valence electrons.
C. Na has two fewer valence electrons than Ca.
D. Na has one fewer valence electron than Ca.
Bond Formation

Answer 1

1)A period in the periodic table is a horizontal row. All elements in a row have the same number of electron shells. ... Periods are horizontal rows (across) the periodic table, while groups are vertical columns (down) the table. Atomic number increases both as you move down a group or across a period.

2)D)Na has one fewer valence electron than Ca.