Hope this helps! If you dont understand balancing equations in general, say so in the comments, I’m happy to help
Answer:
1. Rubidium metal reacts very rapidly with water to form a colorless basic solution of rubidium hydroxide (RbOH) and hydrogen gas (H2).
2. Rubidium sinks because it is less dense than water. It reacts violently and immediately, with everything leaving the container. Rubidium hydroxide solution and hydrogen are formed.
2.43 kilograms is equal to 2430 grams because 1 kilogram is equal to 1000 grams.