Why are sodium (Na) and potassium (K) in the same group on the periodic table? (1 point
a They are both hard and brittle.
b They have similar atomic weights.
c They have similar reactivity.
d They are both colorless.
c They have similar reactivity.
c They have similar reactivity.
The correct answer is c) They have similar reactivity.
To understand why sodium (Na) and potassium (K) are in the same group on the periodic table, we need to consider their electronic configurations and chemical properties.
Both sodium and potassium belong to Group 1, also known as the alkali metals. Group 1 elements share similar characteristics because they have one valence electron in their outermost energy level. This single valence electron makes them highly reactive and eager to lose this electron to form a positive ion.
Sodium and potassium have similar electronic configurations, with sodium having an atomic number of 11 (1s2 2s2 2p6 3s1) and potassium having an atomic number of 19 (1s2 2s2 2p6 3s2 3p6 4s1). In both cases, their valence electron is in the 3s orbital. This similarity in electronic configuration leads to similar chemical behaviors and reactivity. For example, both sodium and potassium readily react with water to form hydroxides and release hydrogen gas.
Therefore, the correct answer is c) They have similar reactivity.