Question

Decide whether the following processes represent physical changes, chemical changes, or both. Indicate your choice with a P for physical, a C for chemical, or a B for both in the available blank.

1) magnetizing an iron nail

2) burning propane in a barbecue   

3) milk spoiling   

4) mixing cocoa powder into hot water to make hot chocolate

5) frying an egg

Answer the following questions regarding atomic structure by filling in the blank. If a charge is requested, please use the convention discussed in class (i.e. 2+ or 3-) for your answer to have the correct format.

What is the atomic symbol for an ion with a mass number of 71, 28 electrons, and a 3+ charge? ___________

What is the mass number of an ion with an atomic number of 50, 48 electrons, and 69 neutrons? ________

How many neutrons are in the nucleus of an ion with a mass number of 31, 15 protons, and 18 electrons? ____________

What is the charge on an ion that has a mass number of 79, 45 neutrons, and 36 electrons? ____________

What would you call two atoms which have the same atomic number but different mass numbers? ____________

Answer 1