Why are sodium (Na) and potassium (K) in the same group on the periodic table? Responses They have similar reactivity. They have similar reactivity. They are both colorless. They are both colorless. They are both hard and brittle. They are both hard and brittle. They have similar atomic weights.
The correct response is: They have similar reactivity.
Sodium (Na) and potassium (K) are in the same group on the periodic table because they have similar reactivity. This means that they both tend to react in similar ways chemically. Additionally, they are both colorless and both have similar atomic weights. However, it is important to note that they are not both hard and brittle - they are actually soft and malleable metals.
Sodium (Na) and potassium (K) are both in the same group on the periodic table, specifically Group 1 (the alkali metals). There are a few reasons for this:
1. Similar reactivity: Sodium and potassium have similar chemical properties and reactivity. They both belong to the alkali metal group, which means they readily give up their outermost electron to form positive ions. This similarity in reactivity is why they are often found in similar compounds and have similar reactions.
2. Atomic weight trend: Another reason for placing sodium and potassium in the same group is their atomic weights. Group 1 elements show a trend in increasing atomic weights as you move down the group. Sodium has an atomic weight of 22.99 grams per mole, while potassium has an atomic weight of 39.10 grams per mole. This trend of increasing atomic weight helps to categorize elements in the same group.
It's important to note that the responses mentioning color, hardness, and brittleness are incorrect in regards to the placement of sodium and potassium in the same group.