Question

1. interpret data look up the densities of the elements in group 1a on page r2. which group 1a elements are less dense than pure water at 4°c?

Explanation:

Step1: Recall water density

The density of pure water at 4°C is 1 g/cm³.

Step2: Look up Group 1A elements densities

Lithium (Li) has a density of about 0.534 g/cm³, sodium (Na) has a density of about 0.971 g/cm³, potassium (K) has a density of about 0.862 g/cm³, rubidium (Rb) has a density of about 1.532 g/cm³, cesium (Cs) has a density of about 1.879 g/cm³, francium (Fr) is radioactive and very rare but estimated to be denser than water.

Step3: Compare densities

Elements with density less than 1 g/cm³ are less dense than water at 4°C. So lithium, sodium and potassium are less dense than pure water at 4°C.

Answer:

Lithium, sodium, potassium