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.
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.
Answer:This quest took a huge leap forward in 2000 when Hubble studied the exoplanet HD 209458 b, the first extrasolar planet known to make “transits” across the face of its star. Hubble became the first telescope to directly detect an exoplanet's atmosphere and survey its makeup.
