Multiple ChoiceHow many protons and electrons are present in a neutral atom of strontium (Sr)?31views
Multiple ChoiceAn atom of calcium contains 20 protons. How many electrons does it have in its neutral state?45views
Multiple ChoiceAn atom has an atomic number of 15 and a mass number of 31. How many protons are present in this atom?43views
Multiple ChoiceIs it accurate to say that a textbook is about 99.9 percent empty space, based on the structure of atoms?27views
Multiple ChoiceThe atomic number of boron is 5. What is the mass number of a boron atom that contains 4 neutrons?33views