Elements in groups 1A through 8A (the main groups of the periodic table) have certain similarities. The correct options that apply are:
d - they all have the same number of valence electrons.
e - they all have similar properties.
Here’s a brief explanation:
- d: Elements in the same group have the same number of valence electrons, which determines their chemical reactivity and properties.
- e: Elements in the same group often have similar chemical properties due to their similar electron configurations.
The other options do not accurately describe commonalities across these groups:
- a: They were not all discovered around the same time.
- b: They do not all have the same oxidation states; this varies between groups.
- c: They do not all have the same number of energy shells; that varies, especially for elements across different periods.