True or false? The first three elements in group 1 of the periodic table are less dense than water.

Analysis of Density of Group 1 Elements

1. Identify the Elements: The first three elements in Group 1 (alkali metals) of the periodic table are:

   • Lithium (Li)
   • Sodium (Na)
   • Potassium (K)

2. Determine Densities:

   • Lithium: Approximately $0.53 \, \text{g/cm}^3$
   • Sodium: Approximately $0.97 \, \text{g/cm}^3$
   • Potassium: Approximately $0.86 \, \text{g/cm}^3$
   • The density of water is $1 \, \text{g/cm}^3$.

3. Comparison:

   • Both Lithium and Potassium have densities less than that of water.
   • Sodium, having a density of $0.97 \, \text{g/cm}^3$, is also less dense than water.

Conclusion

Since all three elements (Lithium, Sodium, and Potassium) have densities less than $1 \, \text{g/cm}^3$, we conclude that the statement is True.

Final Answer

True. The first three elements in group 1 of the periodic table are less dense than water.