An atom has 42 protons, 44 neutrons, and 42 electrons. What is the charge of the atom’s nucleus?

In a popular classroom demonstration, solid sodium is added to liquid water and reacts to produce hydrogen gas and aqueous sodium hydroxide. part a write a balanced chemical equation for this reaction. express your answer as a chemical equation. identify all of the phases in your answer.

13. calculate the initial concentration (before precipitation) of carbonate ions after the addition of each 0.05 ml of solution b to the 1.00 l beaker of solution a. divide the work among group members and write the answers in the table in model 3. assume the volume change as solution b is added is negligible. 14. notice the initial concentrations of zn2+ - and cu2+ in the table in model 3. a. explain how these were obtained from the data in model 2. b. as solution b is added and precipitates form, do these initial concentrations change? 15. use the data in model 2 to indicate the presence of precipitate (either znco3 or cuco3) after each 0.05 ml addition of solution b in model 3. 16. use the initial concentrations of carbonate ions and zinc ions to calculate the reaction quotient, qsp for the zinc carbonate scenarios in model 3. divide the work among group members and write the answers in the table in model 3. 17. use the initial concentrations of carbonate ion and copper(ii) ions to calculate the qsp for the copper(ii) carbonate scenarios in model 3. divide the work among group members and write the answers in the table in model 3.

Which best explains why an iceberg floats?