Question

The atomic number of beryllium (Be) is 4, and the atomic number of barium (Ba) is 56. Which comparison is best supported by this information?

A: They are in the same group because they have similar atomic masses, but they are in different periods because they have different chemical properties.
B: They are in the same group because they have similar chemical properties, but they are in different periods because they have very different atomic numbers.
C: They are in the same group because their atomic numbers are each multiples of four, but they are in different periods because they have different chemical properties.
D: They are in the same group because they have similar atomic masses, but they are in different periods because they have very different atomic numbers.

Answer 1

The answer is:

B)They are in the same group because they have similar chemical properties, but they are in different periods because they have very different atomic numbers.

The explanation:

The vertical columns on the periodic table are called groups or families because of their similar chemical behavior. All the members of a family of elements have the same number of valence electrons and similar chemical properties.

A period is a horizontal row of elements on the periodic table. For example, the elements sodium ( Na ) and magnesium ( Mg ) are both in period 3. The elements astatine ( At ) and radon ( Rn ) are both in period 6.