If a platinum atom has 78 protons. how many electrons does it contain?

Which best represents the law of conservation of mass ?

In a system with only a single force acting upon a body, what is the relationship between the change in kinetic energy and the work done by the force? answers: work is equal to the change in kinetic energy. work depends on the square of the change in potential energy. work is equal to the negative of the change in kinetic energy. work is equal to the square of the change in kinetic energy

Which of the following compounds would be primarily ionic? methane, ch4, ammonia nh3, calcium chloride, cacl2, or carbon dioxide, co2